No Confidence in the Flesh

No Confidence in the Flesh

16 November, 2025

Thesis: God calls us to cast out works righteousness and trust completely in the son of promise.

Summary: The sermon began with the preacher sharing his personal joy over his daughter's recent decision for salvation, which he presented as an answer to long-held prayers and a result of consistently sharing the gospel without coercion. He then introduced the main biblical text from Genesis 21:8-34, framing the narrative of Ishmael and Isaac as an allegory for the incompatibility of works-righteousness and grace. Reviewing the birth of Isaac as a miraculous gift, the preacher highlighted the divine mandate for Ishmael's expulsion, interpreting it as a theological separation necessary for the covenant line. Drawing heavily on Paul's teaching in Galatians 4, he expounded on Ishmael representing the Old Covenant, law, and human effort (flesh), while Isaac symbolized the New Covenant, grace, and divine accomplishment (spirit). The preacher detailed how this allegory highlights the incompatibility of trusting human effort with relying on divine accomplishment for salvation, sanctification, and effective ministry. The sermon concluded by urging the casting out of all forms of self-reliance, emphasizing sole reliance on Christ's finished work, and referencing Ishmael's eventual blessings as a testament to God's general goodness.

Sermon

All right. Well, Layla has an important announcement to make to the church this morning. Tell them.

I got saved.

Well, normally she’s not a woman of few words, but she has this morning. But those are the most important words. All right. That’s commendable. Allow me to elaborate a little bit on that.

As you all know, that is a prayer I have prayed for both of my children. Before they were born, I’d say even before they were conceived, I prayed that God would save my children. And that alone, seeing my family saved, knowing that they are now followers of Jesus, knowing that they have a home in heaven, that means everything to me. You couldn’t give me all the money on this planet, or anything else, that I would ever trade for knowing that my children are walking in the truth.

And I do not force, I do not emotionally manipulate, I do not pressure anyone to be saved. The Holy Spirit can speak to people’s hearts, and he does. And when the time is right, they’ll be saved. I simply make the gospel clear, as I have done with my children since the day they were born. I invest time praying with them, reading the Scriptures to them, explaining what the gospel is every day on their way home from school. And I consistently ask them, what is the gospel? How are we saved? Why do we need to be saved? Just because I’m a preacher, and going to church, and being baptized, and all these good things, that doesn’t make you a Christian. I’ve drilled that into their heads every single day.

And I prayed, Lord, at the right time, I want to see the fruit of this labor. I want to see them saved. And it was Monday. Monday afternoon after school, Layla came up to me and said, “I want to be saved.” I had not taught. I had not talked to her about it. I had not pressured her. I had not said, you know, your friends are getting saved; you need to be saved too. No manipulation. Let the Holy Spirit do his work, and he will draw his own to himself. She said, “I feel something inside of me. I feel something inside of me, and I want to ask Jesus to be my Savior because I’ve been talking to him at night about getting saved.”

So I’m like, you know what that is? That’s the Holy Spirit bringing you conviction but also bringing you to saving faith. And in her own little words, she asked the Lord to be her Savior. She said, “I give my life to you. You are my Lord, to live for you.” So I was like, man, that’s the nature of true conversion, isn’t it?

So I praise God. I praise God, friends, for my prayers to save both of my children. And we will do a baptism. We will do a joining of the church. And as soon as we have some time to do that—I know we’ve got a lot going on—but that is what the church is here for. And we will plan a date for the baptism and allow her to join as a member of our congregation. I give thanks for my children’s salvation, which reminds me to cast out works righteousness and trust completely in Jesus Christ, the Son of Promise.

But I just wanted to share that this morning. I praise God for that. He has answered my two biggest prayers already. If I were to die right now, I could say it is well with my soul. I can say that my dreams have come true. Everything else is merely icing on the cake. Every bit of it. So I give God the glory this morning.

So this morning we’re going to be in the book of Genesis, chapter 21, and we’re going to be looking in verse 8 through 34. Interesting subject we’re going to study this morning. We’re going to explore Ishmael and Isaac, the two sons of Abraham, and examine how we put no confidence in the flesh but rather embrace the promise by faith. Our main theme this morning is that God calls us to cast out works righteousness and trust completely in the Son of Promise. Cast out works righteousness. Trust completely in the Son of Promise.

Now last week, we witnessed a remarkable contrast in chapter 20. We looked at Abraham’s act of faithlessness—his deliberate choice to repeat a lie he had told 25 years earlier, claiming Sarah was his sister. But then we read about how God restored him. God called Abraham a prophet. And despite Abraham’s faithlessness, God was still faithful. God still came through.

And in the first seven verses of chapter 21, we see that Isaac is finally born. God kept His word. God gave Abraham the age of 100, and Sarah at the age of 90—the promised son, whom they name Isaac. And Isaac, of course, means laughter. We learn that Isaac’s birth is a picture of our own salvation. How we are born not of the will of the flesh, nor of the will of man, but of the will of God. It is a picture of salvation that comes by God’s grace. Isaac was a gift from God to Abraham and Sarah. And likewise, our salvation is a gift of grace—not through effort, not through human scheming, not through merit, not through deserving, but simply by believing in the promises of God and embracing this salvation by faith alone.

But today we’re going to see what happens with these two boys—Isaac and Ishmael—and we’ll learn that Ishmael had to be cast out of the house. Just as Isaac’s birth was a divine act of grace, so too must we recognize that our salvation is not through human effort but through God’s promise. Works and grace are incompatible; flesh and faith cannot rule in the same heart. Therefore, works must be cast out to allow grace to reign. We must put no confidence in the flesh but rest wholly in the finished work of Christ. Isaac, the better son of promise, embodies this truth.

In this story, we’ll explore the stark contrast between law and grace, as well as the tension between the old covenant and the new covenant. We’ll examine the conflict between the flesh and the spirit, the struggle between striving and resting, the battle between earning and believing, the clash between human achievement and divine accomplishment, and the division between merit and promise. I know that’s a lot to take in, but we’ll weave these themes together to reveal their interconnected significance.

So let’s open our Bibles to Genesis 21. Let’s begin reading in verse 8.

“So the child grew and was weaned”—speaking of Isaac—“and Abraham made a great feast on the same day that Isaac was weaned.”

Sounds like a party, doesn’t it? Oh, but all is not well. “And Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, scoffing.” Therefore she said to Abraham, “Cast out this bondwoman and her son. For the son of this bondwoman shall not be heir with my son, that is, Isaac.” And the matter was deeply displeasing to Abraham because of his son.

But God said to Abraham, “Do not let it be displeasing in your sight because of the lad or because of your bondwoman. Whatever Sarah has said to you, listen to her voice; for in Isaac your seed shall be called. Yet I will also make a nation of the son of the bondwoman, because he is your seed.”

So Abraham rose up early in the morning, and took bread and a skin of water and put it on her shoulder and gave it and the boy to Hagar, and sent her away. Now this may sound familiar—similar to what happened in chapter 16. And she departed and wandered in the wilderness of Beersheba. The water in the skin was used up, and she placed the boy under one of the shrubs. Then she went and sat down across from him at the distance of about a bow shot. For she said to herself, “Let me not see the death of the boy.” So she sat opposite him and lifted her voice and wept.

And God heard the voice of the lad. Then the angel of God called to Hagar out of heaven and said to her, “What is this, Hagar? Fear not, for God has heard the voice of the lad where he is. Arise, lift up the lad and hold him with your hand, for I will make him a great nation.” Then God opened her eyes, and she saw a well of water. She went and filled the skin with water and gave the lad a drink. So God was with the lad, and he grew and dwelt in the wilderness and became an archer. He dwelt in the wilderness of Paran, and his mother took a wife for him from the land of Egypt.

What a story. Sometimes Abraham’s life reads kind of like a soap opera, doesn’t it?

Let’s move to point number one. We see first the separation of Ishmael and Isaac. That symbolizes the separation of the flesh and the promise.

Now, I’ll admit I struggled to find the perfect opening illustration, but this is the best I could come up with, okay? Have you ever had high expectations for a party or a celebration? Maybe it’s a party. Maybe it’s a celebration. We’re coming along the holiday season, and maybe you’re expecting family to come, with Thanksgiving on the horizon. As Baptists, we love to eat, right? It’s a reason to celebrate, a reason to be thankful—just have all our good food, right? Or maybe it’s a Christmas gathering, and you’re really excited, but you’ve got this one family member who seems to ruin everything, who wants to talk politics or argue and just poops the whole party.

Well, that’s kind of what happened here. At Isaac’s weaning feast, we see a time of joy and celebration—a party, if you will—spoiled by this party pooper named Ishmael. This moment mirrors the broader theme of the separation between flesh and promise, as Ishmael’s presence disrupts the divine plan unfolding through Isaac, highlighting the tension between human desires and God’s covenantal purposes.

Now, let’s talk about this weaning feast. In ancient culture, the weaning feast was a significant celebration, marking a child’s transition to solid food and their integration into family life. It was a time of joy, symbolizing the child’s readiness to thrive beyond dependence on their mother’s milk. Abraham would have been celebrating the fulfillment of God’s promise to give him a son named Laughter—no doubt filled with laughter and rejoicing at this party. Some Jewish rabbis noted that the feast symbolized God’s deliverance of the child from infancy’s dangers, reinforcing the belief that God had kept His promise to Abraham. This feast was not merely a family event—it was a public declaration of God’s faithfulness and a foreshadowing of the covenant’s fulfillment. The feast served as a public testimony to God’s covenantal faithfulness, witnessed by all present.

So this was a party. All the who’s who’s in the land were here. It was a time of eating and drinking and laughing and celebrating. God has kept His word. Here is my covenant heir. And by the way, I’m 100 years old and I got a kid. That’s pretty awesome. God has been good.

Oh, but all is not well. Here the party pooper rears his head. Sarah, the ever-observant mother. Moms know everything, don’t they? They see everything. They hear everything. Nothing escapes their attention. And she notices the son of Hagar, the son of the slave, mocking Isaac.

Now, Ishmael would have been around 16 to 17 years old at this time. And he is poking fun, mocking, or laughing at a two-year-old. It’s very mature of him, isn’t it? It’s actually in Hebrew. In Hebrew, it’s a play on words. He was Isaacing Isaac. He was laughing at Isaac—laughing at laughter, mocking him, scoffing him. This wasn’t mere teasing, as older siblings might do with younger ones. This was bullying directed at the promised child. Paul says in the book of Galatians that he was persecuting the son of the promise.

Now, think about how Ishmael may have felt. He was likely both jealous and envious that Isaac gets such a party. He was the son of the promise. I’m the firstborn. But God is going to make His covenant promises to and through Isaac. And so he’s angry. He resents Isaac. This jealousy and resentment reflect a deeper spiritual conflict over God’s chosen lineage. Sarah comes up to Abraham and says, “You must cast this bondwoman out. I’m not going to put up with her son picking on my son.” He is persecuting him, just as Hagar years ago also persecuted me because she got pregnant, and she knew that I couldn’t have a child. He must go. You must cast this bondwoman out because he has no inheritance rights with Isaac.

Now, verse 11. This thing displeased Abraham. No doubt. Think about it, dads. Ishmael was Abraham’s son too. He had loved Ishmael for 16 or 17 years. It had been him and Ishmael. He was the joy of his old age. He was initially the apparent fulfillment of God’s promise, wasn’t he? But now he must send him away, possibly, and more likely than not, never to see him again. He must cut ties with his firstborn.

Now, Abraham knows that Ishmael was born through Abraham’s scheme and through his own impatience. But Ishmael was still Abraham’s flesh and blood. And to send him away feels cruel and heartless. Nevertheless, God says, listen to the voice of your wife, because she’s right. God’s lady said, amen. Listen, husband, she’s right. And she was right. Because Isaac was the one through whom the nations would be blessed, ensuring the covenant line continued through him. He is the covenant child. He is the son of promise.

Now, Sarah isn’t being vindictive or jealous, even though she may have had some of these emotions. God is, through Sarah, ordaining a separation that has to happen for the covenant line to continue through Isaac. However, this morning we’re going to see that there must come a separation between Ishmael and Isaac. For theological reasons. For spiritual reasons. Even for gospel reasons.

Why? What on earth did this ancient text about a party gone horribly wrong possibly have to do with us in Pilot Mountain, or Westfield, or wherever you’re from? What on earth does that have to do with us today? We must know that something very significant, something profound, is being taught here. We are being taught about the nature of salvation. About the incompatibility of works and grace. About the absolute distinction between living in slavery to the flesh and living in the freedom of the spirit. Friends, Isaac and Ishmael cannot live together. They can’t.

I want you to remember that phrase. Isaac and Ishmael cannot live together. They both cannot inherit the promise, have the inheritance, or live in the house. One must stay, and the other must go.

Now remember, Isaac is born not by human power but by grace through faith in the promises of God. He is a gift. Ishmael, on the other hand, was born by the cunning and plotting of Abraham and Sarah—born not by faith in God’s promises, but by fleshly desire and human effort. He is a product of misplaced trust in God’s timing and a result of human schemes. So, you know, I could spend hours trying to figure out what on earth this has to do with us in the New Testament. How can I possibly make such a correlation between Isaac and Ishmael? Good news—I don’t have to. Because the Apostle Paul already did. In Galatians 4, Paul directly applies this Old Testament story to show that true inheritance comes not through human works or fleshly lineage, but through faith in Christ alone. That’s the heart of the gospel: casting out works righteousness and embracing grace through faith.

So turn with me to Galatians chapter 4. We’re going to see how Paul in the New Testament interprets this passage in the Old Testament in light of gospel truth. This is Paul’s interpretation, and it’s much better than anything I could ever come up with on my own, because Paul is writing under the inspiration of the Holy Spirit.

Paul is writing to the Galatians. The Galatians are believers. He’s writing to a whole group of churches in Galatia. They have placed faith in Christ. But there’s a group called the Judaizers who have infiltrated their churches and are preaching a Jesus plus gospel. Yes, believe in Christ. You also have to be circumcised. You also have to keep all the law of Moses. You also have to keep all the dress and dietary restrictions. It’s Jesus plus this, this, this, this, and this in order to be saved. Paul is writing to the Galatians and saying absolutely not. Salvation is by grace alone, through faith alone, in Christ alone. Hallelujah and amen forever and ever.

He uses this Old Testament story. We’ll read from verse 21 to 31, then examine each verse. He says, “Tell me, you who desire to be under the law, do you not hear the law? For it is written that Abraham had two sons, one by the bondwoman, but the other by the free woman.” That is, one by Hagar, one by Sarah. “But he who was of the bondwoman was born according to the flesh, and he of the free woman through promise.” That’s Isaac. “Which things are symbolic. For these are the two covenants: the one from Mount Sinai, which gives birth to bondage, which is Hagar. For this Hagar is Mount Sinai in Arabia and corresponds to Jerusalem which now is, and is in bondage with her children. But the Jerusalem above is free, which is the mother of us all.”

Skip down to verse 28. “Now we, brethren, as Isaac was, are children of promise.” But the one born according to the flesh persecuted the one born according to the Spirit. Even so it is now. He said nothing has changed. Ishmael will always mock and persecute Isaac. The flesh will always oppose the Spirit. Law will always run headlong against grace. Nevertheless, what does the Scripture say? “Cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the free woman.” So then, brethren, we are not children of the bondwoman but of the free. And then he says, therefore, stand fast in the liberty by which Christ has made us free.

This is a lot to unpack, isn’t it? What on earth are you talking about, Paul? Let’s talk about it.

Two sons—this is an allegory of two covenants. Paul is saying faith and flesh cannot coexist in the same heart. Grace and works cannot share the same throne. The promise and human effort cannot both receive salvation. That is the inheritance by faith. Friends, this is not about ethnicity. This isn’t about Arabs versus Israelis. This is about salvation. It’s about how we are made right before God. It’s about justification.

So we see this paradigm in Scripture. We see the flesh—represented by Ishmael—versus the Spirit, Isaac. We have two different covenants. Hagar and Ishmael represent Mount Sinai, the place where the law was given. Remember? The Judaizers were saying you have to keep the law in addition to believing in Christ. Paul was like, you think salvation comes through keeping the law? Good luck. Because every one of us are law-breaking sinners. That’s the reason why there’s thunder and smoke and the wrath of God. And if you think you can approach that mountain in order to get to God, you will be stoned or killed in an instant. The law demands obedience as the path to life, promising divine favor and eternal reward through perfect compliance. It requires flawless performance and offers life only through works. Oh, but that’s bad news because by the deeds of the law, no flesh can be justified—since all have sinned and come short of the glory of God.

Isaac represents the covenant of grace, the new covenant. In verse 26 he says, this Isaac represents the Jerusalem which is above. So Sarah and Isaac represent the heavenly city. They represent a covenant of grace. In contrast, the law says do this and live; the gospel says believe this and live. It offers righteousness as a gift, provides salvation by faith, and promises life through the work of another—through the righteousness of another, namely the Lord Jesus Christ. It receives His righteousness as a gift by faith, just as Abraham and Sarah received Isaac as a gift. The law says do. The gospel says done. It is finished. Our sin debt has been paid. Atonement has been made. Justice has been satisfied—all by the Lord Jesus Christ. We are justified by grace through faith in Christ. And this grace covenant saves completely. It pardons all of our sins, credits us with Christ’s righteousness, and gives us peace with God.

But friends, you cannot be under two covenants. You can’t be trying to keep the law and trusting Christ at the same time. You can’t be under the old covenant and enjoy the benefits of the new covenant. You can’t have Ishmael in the house and Isaac in the house at the same time. Just as Ishmael represents life in the flesh, so too does the attempt to add works righteousness to grace. If you try to add to the gospel, you take away from it. When you attempt to add your own works, your own merits, or your own sense of deserving to grace, you actually undermine it. Grace can never be added to.

They represent two distinct paths: life in the flesh, as exemplified by Ishmael, and life in the Spirit, as exemplified by Isaac. Ishmael represents life in the flesh. Human effort. Self-reliance. The striving of the flesh. Remember how Ishmael came about? God’s not keeping His promise. God’s slow about keeping His promise. I need an heir. Abraham, you take my servant Hagar. Go into her. Abraham did. He slept with Hagar and Ishmael was conceived and Ishmael was born. This is the work of doubt. The work of the flesh. Human striving. And Paul says that the flesh cannot please God. The carnal mind is an enemy with God. It cannot be subject to the law of God. It always insists on its own way. And the flesh cannot please God. No matter how religious it is. No matter how sincere it is. No matter how hard it tries. No matter how hard you try to clean up your life and do better. You cannot defeat the flesh. You cannot defeat sin, and you cannot merit perfect righteousness before God. Ishmael cannot inherit the promise.

Isaac, however, represents life in the Spirit—divine power, God’s ability, and supernatural birth. Verse 29: Isaac was born after the Spirit. It was not by human effort, but by a divine miracle. God had to intervene, giving life to Sarah’s dead womb. God had to do what only He could do. In our salvation, we are trusting God to do what only He can do. We cannot save ourselves. As Jonah says, salvation is of the Lord. From beginning to end, it is God’s work. What is our part to play in it? To believe and to receive it by faith.

But this also speaks of how we live our Christian life. Not only our justification, but our sanctification is also by grace through the Spirit. Paul writes in Galatians 5:16, “Walk in the Spirit, and you shall not fulfill the lust of the flesh.” Believers, listen—you cannot defeat the flesh by trying harder. You can only defeat the flesh by walking in the Spirit. You can only enjoy the benefits of being a child of God by being led by the Spirit of God. By resting in His power. By trusting in His work. Because trying to live the Christian life apart from the Spirit is exhausting. You will end up depressed, despondent, and burned out. It’s impossible without the Spirit. That’s why, as believers, we are commanded to be filled with the Spirit, to yield to the Spirit, to walk in the Spirit. You can read that in Ephesians 5 and Galatians 5. It’s the Spirit of God who gives believers victory over those besetting sins, who equips us for service, who gives believers gifts to serve the church, who empowers us to be witnesses, who seals our very souls to the day of redemption.

So as Paul speaks to the Galatians: Why on earth, having been justified by faith, are you trying to live in slavery again? When you have Isaac, why are you clinging to Ishmael? When God has already justified you and sealed you and filled you with the Spirit through faith, why on earth are you trying to earn and merit favor and good standing with God? Why are you trying to live the Christian life in your own power? That is Ishmael, and he must go.

And so we represent two distinct identities. One is slave. One is free. Hagar is a slave, and Ishmael is born in slavery. He may be a biological son of Abraham, but his identity is still one of a slave. And friends, before we were believers, and if you are an unbeliever, you are a slave this morning. You are a slave to sin. You say, “No, I’m not. I’m free. I can make my own decisions. I can do whatever I want to.” You are free. You are free to choose any sin you want, because that’s the only thing you can ever do. You can’t do good if you tried. Even your goodness is tainted by sin. Even at your best you are clothed in filthy rags before a holy God. You must have the righteousness of Christ. You must cast off Ishmael and you must embrace Isaac.

But we, when we come to Christ, become children of promise like Isaac. We become free. Truly free. And our identity is found in Christ. True freedom. True life. True satisfaction. True purpose comes from Christ. We are free from sin. We are free from its penalty. We are free from its punishment. We are free from its power. And praise God, one day we will be free from its presence. I can’t wait for that day. But we are free. If the Son makes you free, you are free indeed. So stand fast in the liberty wherewith Christ has made you free.

If you are an Isaac, do not try to be an Ishmael. You have received the adoption of sons when you believe. God sends the Spirit of His Son into your heart that cries out, “Abba, Father.” Think about that. You have the God who spoke the universe into existence as your Father. You are accepted. You are beloved. You have a new name, a new nature, a new home, a new purpose. Why on earth would you try to embrace being an Ishmael when you are an Isaac? So believers, stop trying to earn your way into the family. Stop trying to earn your keep in the family and trust in the work of the Son of Promise.

One is scheming and the other is believing. We’ve already touched on this. Ishmael is the product of human wisdom, a fleshly strategy—religion embodies this very approach. If I try harder, if I stop drinking or stop cussing, try to change my heart, then maybe God will accept me. Friend, you can’t do it. You cannot do it on your own. Isaac, instead, is the product of believing. What does God require of you this morning? To believe in the Lord Jesus Christ, and you’ll be saved. Let Him transform your heart. Stop trying to turn over a new leaf. Stop trying to change yourself. You can’t do it. You must come to Christ. You must embrace salvation by faith. And let Him change you from the inside out.

One is salvation by works. The other is salvation by grace. Ishmael, of course, represents salvation by works. Ishmael says, “I must earn God’s favor. I must achieve righteousness. I must perform well enough to be accepted. Or I must maintain my salvation through my obedience.” Friends, Paul writes again and again: “We will never be justified or sanctified in our own power. But by faith in Christ.” Isaac and Ishmael represent two different paths—salvation by works, salvation by faith.

Now in the immediate context of Galatians, Paul is addressing these Galatians and he said stop turning to holy days and feast days and the law of Moses and circumcision in addition to Christ in order to be saved. What does that look like in modern times? It looks like I’m trusting my good works. As long as I’m better than the next guy. Or I’ve joined the church and I’m baptized. Or I’ve been on mission trips. Or I give to the offering. Or I’m a deacon or a pastor or Sunday school teacher. Or I’ve shared the gospel. I’ve been faithful to evangelize this week. None of those things can get you into heaven. They’re good. But they become idols if they are substitutes for the finished work of Christ.

Isaac instead is born by grace through faith in God’s promise. Isaac represents receiving salvation. Abraham and Sarah contributed nothing—only belief. They had to trust God’s promise. God did the work. It was impossible for Sarah to have a child, and it’s impossible for us to save ourselves. God must bring life to dead souls, just as He brought life to Sarah’s dead womb. God fulfilled His promise and produced the heir. Likewise, God produces our salvation. Friends, you see, our salvation isn’t 99% God and 1% us. Some people think they had a hand in their salvation, that they helped God out a little. Maybe God looked through time and saw I’d be a good Christian. Or maybe He saw I’d believe someday and chose me. No. Long before you were born, long before you did anything good or bad, God had already set His love on you. Salvation is 100% God’s work from beginning to end. He who began a good work in you—by choosing you in eternity past, purchasing you with the blood of His own Son, and sealing you with His Spirit—will also see you all the way through to glorification. Friends, salvation is 100% a work of grace. It is an Isaac work, not an Ishmael work.

One is human achievement, the other is divine accomplishment. Abraham, when he conceived Isaac, he went out. God said, “I didn’t need your help, Abraham.” Isaac, on the other hand, is “I can do nothing; God did all of this.” I love what Jonathan Edwards once said: “We contribute nothing to our salvation except the sin that makes it necessary.” You know what your part in your salvation was? Sinning. You know what God’s part in your salvation is? Saving. That’s pretty good. I’m going to write that down. It just comes to me sometimes.

Isaac and Ishmael represent two distinct inheritances and two contrasting destinies. Let’s clarify this distinction. Ishmael symbolizes earthly Jerusalem, corresponding to Mount Sinai and the keeping of the law—an earthly work, a work of the flesh. Isaac, on the other hand, represents Mount Zion and the heavenly Jerusalem—a heavenly inheritance. One reflects an earthly legacy, the other a heavenly one. As children of promise, like Isaac, we inherit the heavenly portion. We are pilgrims passing through this life, and the Bible teaches that our inheritance is in heaven—being prepared by Christ, incorruptible, undefiled, and reserved for us there. That’s our eternal home.

Now, as children of promise, like Isaac, we have the inheritance. Isaac received Abraham’s inheritance. We inherit our father’s legacy. What greater inheritance could there be than inheriting our father’s name, nature, and home? By the way, I can’t wait to be there. I enjoy the sweet presence of God’s people. But as good as church is, it’s merely an appetizer of what heaven will be like. When we arrive, with glorified bodies and full capacity to enjoy God’s splendor, glory, and goodness, what an inheritance. I would trade anything on earth for that. That is your home—your inheritance as a son or daughter of promise by faith in Christ.

Moving on, what does it look like for Ishmael to live in the house today? Well, in our salvation, we say we trust in Christ alone. But secretly, we’re trusting our own performance—we’re trusting in our own goodness or our family relations. We say we’re saved by grace, but we live as if it’s grace plus our own efforts. Friends, that’s Ishmael living with Isaac. That’s Ishmael trying to inherit the promise. Friends, our salvation is found not in who we are, but in who Christ is. Not in what we have done, but what Christ has done for us.

In sanctification, Ishmael in the house looks like claiming to believe that God is sanctifying you by His Spirit, but you’re exhausting yourself trying to earn His favor with your own efforts. You’re striving in the flesh to please God. And you end up empty, burned out, and collapsing under the weight of your own failure. By the way, I’ve been there. In fact, I live there most of the time. Can I tell you something very personal? I am a very performance-based person, and I expect nothing but sheer excellence out of myself all the time. And guess what? I am not excellent. I am weak. I am flawed. I am a sinner. And if I base my acceptance before God on how well I’m performing, on how I feel, I will never be at peace. I will end up discouraged and depressed and despondent and in despair. I must rest in Christ alone. I must rest in His power. That’s why Galatians and Romans are so precious to me. Just as they were to Martin Luther, who was a German monk who lived for 33 years trying to earn favor with God. And he was exhausted because he knew he couldn’t do this until he read those words: “The just shall live by faith.” So I must preach the gospel to myself every day, and you must preach the gospel to yourself every day. And remember, it’s not based on my obedience or my performance, but on my acceptance and salvation—even my sanctification—because of Christ and Christ alone. It’s by Him living the perfect life I could never live, by dying the death I deserve to die, and by rising from the dead in my place, and Him giving me new life. And now the life I live, I live by faith in the Son of God, through the power of the Spirit, not through the strivings of the flesh. Believers, you must rest in Christ alone. You must find the cross. You must find the work of the Spirit so pleasant, so precious to you. You must rest in Him. You must daily delight yourself in the finished work of Christ. And daily trust.

Ishmael looks like professing faith in God’s provision. But we scheme, lie, and cheat to get ahead. We manipulate circumstances and force God’s timing. We rest on our own plans, wisdom, schemes, and strategies. In Christian ministry—this one hits hard—we claim to serve in the power of the Spirit, yet operate in the energy of the flesh. By the way, in the past couple months, I’ve had a paradigm shift in my soul. I’ve realized I’m not alone and just how worthless I am apart from Christ. I can do nothing. I’ve prayed for God to bring me to desperation—where I don’t rely on how well-studied I am, even though I should study, or how polished my speech is—regardless of grammatical errors. I rely on the Holy Spirit’s power. Let me tell you, that is liberating and freeing. Ishmael in the house looks like trying to do God’s work in our own power—helping God out, or doing our own thing like Abraham, expecting God to bless it. Having our own ministry agenda, our own vision for the church. Pushing our plans and purposes instead of resting and trusting in God’s timing and His plans.

Ishmael in the church looks like using unbiblical metrics to gauge success, such as popularity, budgets, buildings, and butts in the pew. There’s your three B’s—buildings, budgets, and butts in the pews. Let me tell you—this is an Ishmael pretending to be an Isaac. If I have to entertain you and emotionally manipulate you to get you to come to church and stay, that is doing the work of the flesh. That is scheming. That is trying to do God’s work—or maybe just my own work—and asking God to bless it. And friends, God will not bless Ishmael in the church. He blesses only Isaacs. We must do God’s work, God’s way, at God’s time.

So what’s the gospel application? We must cast Ishmael out. The works of the flesh will not share in the inheritance of God. We must part with our cherished sins. Now think about this. This broke Abraham’s heart to send Ishmael away. No doubt. But Ishmael had to go. Friends, there may be some cherished sins. There may be some people in your life you have to be like, you know what? I love you and I’ll pray for you, but I can’t be with you anymore. I can’t hang out with you. I can’t go to those places anymore. Something that you love, and Christ says if you’re going to love me, you’re going to have to part with it because I will have no competition.

Not only must we part with our sins, we must also part with our self-righteousness. Ordinances and traditions we once trusted as a means of justification must be sent away, never to return. We must repent of sin, self-righteousness, and self-reliance—all of these are Ishmaels and must be sent away. We must place no confidence in the flesh, but rejoice only in Christ Jesus.

Ending up here. What happens with Ishmael? Let’s turn back to Genesis. What happens to Ishmael? Oh! A very similar thing that happens in chapter 16. Hagar takes her son and what provisions Abraham has sent. It breaks Abraham’s heart to see his son go. But he knows he must. He cannot dwell with Isaac. He already showed what type of boy he was by mocking Isaac. I mean, if Ishmael continued to live in the house, we may have had another Cain and Abel episode. He must be gone. But God makes a promise to Abraham that because Ishmael is his seed, he will still be blessed. How about that? God is going to bless Ishmael.

It seems Ishmael is on the verge of death. Once again, the angel of the Lord hears the cries of Hagar and Ishmael. Remember the name Ishmael means “God hears.” And God makes a well of water appear in the desert. When he’s on the verge of death, their water has run out. Their food is gone. They have nowhere else to turn. They cry to the Lord. The Lord provides a well of water. His life is spared by God’s intervention.

This story mirrors the call to trust in Christ. Just as God’s covenant with Abraham extended grace to Ishmael despite his status, so too does God’s promise of salvation reach all who turn to Him, not by works but by faith. Even when we are cast out, God hears our cry and provides for our need.

Friends, you may find yourself like Hagar and Ishmael, wandering in the scorching heat of the desert, with no one to turn to and nowhere to go. Friends, cry out to God—because He still hears your prayer. He hears your cry for mercy, your desperation, your brokenness. And He promises. He promises Hagar that Ishmael will grow, that he will become a mighty man, an archer, a man of the desert. He marries a wife from the land of Egypt—Hagar’s home country—and we’ll later read that from Ishmael come twelve sons, who become twelve great tribal leaders. They become the father of the Arab nations. Friends, are they blessed today? Are they wealthy? Are they prosperous? Absolutely. God has still kept His covenant promise with Abraham. And even though Ishmael was not the son of promise, he was still blessed because of his relationship to Abraham. Friends, is God not faithful? Does God not keep His word? Yes, He does. He’s good to the Ishmaels and the Isaacs alike. He showers His goodness equally on all who call upon Him, the just and the unjust. He is good to all. And He gives to all common grace. His mercy is vast, His promises unbroken. Even in the darkest desert, when the sun beats down and the thirst gnaws at your soul, He is there—He hears, He provides, He delivers.

But Ishmael cannot live with Isaac.

As they come and give us a hymn of invitation this morning, I want you to search your own heart urgently. I want you to identify the specific struggles that beset your life. I want you to identify those areas in which you are struggling, trusting in your own scheming and your own devices. And I want you to give them over to the Lord. If you’re lost this morning and you’re trusting in anything other than Christ alone, you need to repent of your self-righteousness. Repent of your self-sufficiency. And trust in the Son of Promise alone. Because it is only in Christ that you will receive the inheritance of heaven.

Believer, if you are struggling to believe that these promises are really yours, as a child of the promise, if you’re struggling believing that these promises are really yours, if you’re having difficulty standing in the liberty that Christ has given you, if you feel the bondage of religion and performance just weighing down on you, come and talk to the Lord. And say, Lord, I want to enjoy all the benefits that belong to those who are children of the promise. I want to preach the gospel to myself and be reminded of its glories. Be reminded of the sufficiency of Christ in my place. You are a child of the promise. You are a work of God. A miracle of grace. Just as Isaac was. So stand fast in the liberty that Christ has given you.

This altar is open. Page 425, “Tell it to Jesus.” Would you stand please.

Are you weary? Are you heavy hearted? Tell it to Jesus. Tell it to Jesus. Are you grieving over joy’s departing? Tell it to Jesus alone. Tell it to Jesus. Tell it to Jesus. He is the greatest of all. You don’t know there’s such a greater brother. Tell it to Jesus alone.

Do the tears fall when your tears have hidden? Tell it to Jesus. Tell it to Jesus. When your sins and demons are hidden, tell it to Jesus alone. Tell it to Jesus. Tell it to Jesus. He is the greatest of all. You don’t know there’s such a greater brother. Tell it to Jesus alone.

Do the tears fall when your tears have hidden? Tell it to Jesus alone. Tell it to Jesus alone. Tell it to Jesus. Do the tears fall when your tears have hidden? Tell it to Jesus alone. Tell it to Jesus alone. Tell it to Jesus. Tell it to Jesus. He is the greatest of all. You don’t know there’s such a greater brother. And we’ll live to Jesus our Lord. Yeah.

Let me share a little secret with you—I had planned on finishing that whole chapter. But guess what didn’t happen? We have to be in chapter 22 next week. I’ve already got my sermons planned out, and we have to be somewhere specifically on the Sunday before Christmas, okay? So we have to be in chapter 22 next week. I will encourage you to go home and read the rest of chapter 21. I’m going to give you the speed notes here, okay? Because even though we didn’t finish the chapter, the message is clear: just like Abraham trusted God with his life, we must trust Jesus alone for salvation. The story isn’t about finishing a chapter—it’s about trusting the One who finishes us.

Remember Abimelech? The king that Abraham lied to? Well, he comes back. And he wants peace with Abraham. He recognizes that God has blessed him. God is with him. So he’s going to be in chapter 22 next week. So Abraham makes a covenant of peace with this same king he lied to. And how does he do that? Well, he digs a well. He gives seven lambs. And he plants a tree. And there he calls on the name of the Lord. And here we learn a new name for God: El Olam, the everlasting God. And he says this well and this tree will be here for perpetual generations. These symbols—this well and this tree—foreshadow Jesus, the living water and the tree of life who fulfills God’s covenant promises. And they will be here for generations, bearing testimony about the faithfulness of the everlasting God when my children and my children’s children and their children come and sit under the shade of this tree and drink from this well. They remember that God is the everlasting God and that He always keeps His promises both now and forever.

But here’s a cool thing. These were symbols of God’s covenant faithfulness—a well and a tree. Friends, He has given them. He has given us symbols of His covenant faithfulness as well. He’s given us not a well in the desert, but the living water in the Lord Jesus Christ who eternally quenches our thirst, just as the well in the desert provided for Abraham’s household. And He gave us not a tamarisk tree, but the tree of the cross at Calvary, where Jesus bore our sins and became our eternal atonement. So if you ever doubt God’s faithfulness, if you ever doubt God’s love for you, just look to the cross and be reminded that the everlasting God loves you with everlasting affection and has everlasting faithfulness to you. So there you go. There’s the rest of the chapter. But go home and read it. It is well worth the read. Just keep those points in mind.