So listen now carefully to God's word from Genesis chapter 21 beginning in verse 8. And the child grew and was weaned, and Abraham made a great feast on the day that Isaac was weaned. But Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, laughing. So she said to Abraham, Cast out this slave woman with her son, For the son of this slave woman shall not be heir with my son Isaac." And the thing was very displeasing to Abraham on account of his son. But God said to Abraham, Be not displeased because of the boy and because of your slave woman. Whatever Sarah says to you, do as she tells you. For through Isaac shall your offspring be named. And I will make a nation of the son of the slave woman also, because he is your offspring." So Abraham rose early in the morning and took bread and a skin of water and gave it to Hagar, putting it on her shoulder, along with the child, and sent her away. And she departed and wandered in the wilderness of Beersheba. When the water in the skin was gone, she put the child under one of the bushes. Then she went and sat down opposite him a good way off, about the distance of a bow shot. For she said, Let me not look on the death of the child. And as she sat opposite him, she lifted up her voice and wept. And God heard the voice of the boy, and the angel of God called to Hagar from heaven and said to her, What troubles you, Hagar? Fear not, for God has heard the voice of the boy where he is. Up, lift up the boy and hold him fast with your hand, for I will make him into 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 boy a drink. God was with the boy and he grew up. He lived in the wilderness and became an expert with the bow. He lived in the wilderness of Paran, and his mother took a wife for him from the land of Egypt. If you would also turn with me this morning, for the sake of clarity, I hope you'll see why this is necessary in due time, to the book of Galatians, Galatians chapter 4. Galatians chapter 4, we'll read verses 21 through 31. Beginning in Galatians 4, 21 we read, Tell me, you who desire to be under the law, do you not listen to the law? For it is written that Abraham had two sons, one by a slave woman and one by a free woman. But the son of the slave was born according to the flesh, while the son of the free woman was born through promise. Now this may be interpreted allegorically. These women are two covenants. One is from Mount Sinai, bearing children for slavery. She is Hagar. Now, Hagar is Mount Sinai in Arabia. She corresponds to the present Jerusalem, for she is in slavery with her children. But the Jerusalem above is free, and she is our mother. For it is written, Rejoice, O barren one who does not bear. Break forth and cry aloud, you who are not in labor. For the children of the desolate one will be more than those of the one who has a husband. Now you, brothers, like Isaac, are children of promise. But just as at that time he who was born according to the flesh persecuted him who was born according to the Spirit, so also it is now. But what does the scripture say? Cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman. So brothers, we are not children of the slave, but of the free woman. Sins are reading God's word. Let's ask his blessing now upon this word in a moment of prayer. Lord, we do come today asking that you would make fruitful our time in your word. We trust that as we read these words, you are speaking. And we pray that your words would penetrate our heart and our minds. That we might understand what is being said to us. That we might believe, and through believing we might be changed into those who love you, place faith in you, and serve you well. We pray this in Jesus' name. Amen. Have you ever had a rival? Someone you've competed against, attempting to best them and get the upper hand. Rivals can be found in many places, so there's many opportunities for such a thing to happen. Maybe it was someone that you competed against during sports in school, whenever that was for you. Maybe it was someone that you worked with at a particular point in your career. You were always trying to impress the boss more than them. Or maybe it was a lifelong rivalry with a sibling or another family member. Whatever the case may have been for you, if this has ever happened, rivals tend to loom quite large in our mind because of all the time and energy that we invest to try to be better than them. So if you had a rival, you probably know him. But you may be the only person in the world who knows about your rivalry. Many rivalries go unnoticed, but some rivalries become iconic. Think Tennessee versus Alabama or Florida. Think Mike Tyson, Evander Holyfield. Think Republicans versus Democrats. Think Coke versus Pepsi. In cases like these, others like them, the competition is so steep and storied that it's hard to think of one of the rivals without the other. They come to be defined in contrast to one another in our minds. Warring parties, eternally locking horns in battle. In congregation, that is the type of rivalry which is found in our text this morning. Last Sunday evening, we expounded upon Genesis 21, 1-8, which told us of the long-awaited birth of Isaac. We've been hearing predictions. We've been hearing promises, chapter after chapter after chapter in Genesis. And finally, after 25 years of promises, Abraham and Sarah finally gave birth to a baby boy. He was the child of the covenant. the one who would inherit the promises of the land, promises of offspring, and promises of blessing. He would receive all of these things in full when Abraham was no longer living. Understandably, that was the cause of great rejoicing for Isaac's parents, who had miraculously brought a baby into the world in their extreme old age. And so Sarah, who had once been skeptical that such a thing was even possible, she now laughed with joy. We saw that. And she invited others to join with her in the celebration. Humanly speaking, no one would have reasonably expected that the Lord would so richly bless her in this way, but He had, and so she was exuberantly happy. But as we come to Genesis chapter 21 verses 8 through 21, we see that the spell of motherly bliss, it didn't last forever. For there was another child competing for Abraham's affection, Ishmael, whom Abraham had fathered with Sarah's servant Hagar more than a decade prior. And this competition would come to a head while Isaac was but a toddler, and it would rapidly become apparent that there was only room enough for one of the boys in Abraham's household. Who would prevail? Well, ultimately God, as we see in our text today, would use the scorn of Sarah to remove Ishmael, the son of slavery, from the household so that Isaac the son of promise, might be the sole inheritor of covenant blessings. So this morning we want to see how this rivalry played out, and we want to come at it from three different angles. We'll consider this rivalry this morning, first of all, as told by Moses, second of all, as interpreted by Paul, and last, as relevant to us. So the rivalry as told by Moses, as interpreted by Paul, and as relevant to us. First of all, let us consider the rivalry as told by Moses. Here we just want to get acquainted with what actually happened, as recorded in the book of Genesis. Now to orient ourselves to the text, we need to recognize right away that there is a chronological leap which takes place between verse 7 and verse 8. In verse 7, Isaac had just been born. Sarah's still rejoicing. But in verse 8, we're told that the child grew and was weaned and Abraham made a great feast on the day that Isaac was weaned. Given what we know about the ancient world, we can deduce with a fair bit of confidence that the chronological leap which happens between these verses was probably about three years. It's fairly common today for children to stop nursing by the time that they're one or so, but this was typically delayed until closer to the age of three or even later in the ancient world. Without the conveniences of baby food and vegetable purees and easy-to-find fruit, a mother's milk remained an important part of the child's nutrition for a long time. And when the child no longer needed this milk and was weaned, it was a cause for great celebration. Because it was a sign that the child was actually going to make it. They were going to survive the treachery of infancy during an age when modern medicine was not around to lower mortality rates. And so it was a time of great joy. This would have been a great feast, a grand party thrown to celebrate the child's entrance into a new stage of life. And it was in that joyful context that controversy arose. According to verse 9, Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, laughing. That was the grand infraction that would enrage Sarah and bring everything to a head. She saw Ishmael laughing. Now that sounds ambiguous and it is, both in English and in Hebrew. The fact that the big problem was Ishmael laughing shouldn't, I don't think, shock us. When we think back on how important laughter has been in the Isaac story. When God first told Abraham that he was going to give him a son in his old age, what did he do? He laughed. And when God told Sarah, she laughed too. As a consequence, God required them then to name their son Isaac. He laughs. And when he was born, Sarah laughed with joy. Now, in our text today, Ishmael joins in on the laughter. But the only problem is that it was not friendly laughter. He was not joining in on the celebration. Some scholars have used the ambiguity here, what he actually did, as a license for a lot of creativity. But I don't think there's anything in the text which would suggest that this word laughter is a euphemism for something else. With Isaac weaned, showing himself to be a capable heir, Ishmael begins to read the writing on the wall. He begins to view Isaac as a rival. And so he antagonizes little Isaac on his special day. He mocks him. He pokes fun at him. He laughs at him, not with him. And Sarah sees all of this. And as this unfolds at his celebratory feast, Sarah immediately begins to put two and two together. She immediately began to realize that Ishmael's prolonged presence was sure to cause a problem for her son. She had given birth to the child of the covenant. But this bigger, stronger boy with a marginal claim on his father's inheritance could prove to be a threat. So she responds like a mother bear protecting her cubs. She lashes out at the perceived threat. She says to Abraham, cast out this slave woman with her son. For the son of this slave woman shall not be heir with my son on it. These words, I think, are revealing, and I think they actually confirm the interpretation that we've taken thus far. It's not so much that Ishmael's actions were uniquely dastardly or anything like that. It's that his actions exposed him as a competitive rival to Isaac. This slave child, the son of a foreign slave woman, might take away that which belonged to her only son. And so she calls on her husband to cast him out. And as we read, understandably, this greatly upsets Abraham. Ishmael may not have been Sarah's son, but he was Abraham's son. He loved the boy. He felt great compassion for him. Even though God had already, at this point, alerted him to the distinction that existed between the two. and perhaps left to his own devices, Abraham would have ignored Sarah and waited for tempers to settle down so that he might continue to keep the family together. But he's not given a chance because God comes to him, apparently in the night, and tells him that he needed to drop his displeasure and do as Sarah had said. He was indeed to cast out the slave woman with her son. Why? Because in her scornful fit, Sarah was right about one very important thing. Isaac was the child of the covenant. He was the child of promise, and through him would Abraham's offspring be named. Ishmael would have no part in any of that. Nor would he be allowed in the long run to act as some sort of co-inheritor. Isaac was not to play the role of executor of a state and dole things out to others. No, he was to receive it all himself. Sure, God would keep his promise from Genesis chapter 16 to make of Ishmael a nation. He assures Abraham of this. That's one of the reasons that he didn't need to be displeased. But Ishmael's prosperity would always only be temporary and earthly, rather than eternal and spiritual. We saw the beginnings of that back when we examined the story of Ishmael's birth in Genesis 16. Ishmael would be blessed because of his relationship to Abraham, but not in the same way that Isaac was to be blessed. And so when Abraham woke up, he did as he was told. He took bread, he took a container of water made of animal skin, and he placed all of this on Hagar's shoulders, and he turned Ishmael over to Hagar's custody, entrusting him to her care. And then he sent them off, leaving them to wander in the wilderness of Beersheba, which was a region to the south of Canaan, closer to Arabia. Some have, and I think there's something to this perhaps, some have speculated that even in this action we see glimpses of Abraham's love for Hagar and Ishmael. And he could have, if he wanted to, he could have loaded down donkeys, he could have supplied a caravan full of supplies to take them to their new home, but he doesn't. He sends them off with only what they can carry, perhaps in the hope that they wouldn't make it far. Maybe he was scheming to make sure that they were able to set up camp close by. Somewhere that he could continue to visit, continue to maintain his relationship with Hagar and Ishmael. But that is not what happens. Hagar and Ishmael begin wandering in the wilderness, and as soon as their water is gone, the trouble begins. Hot sun starts to beat down on them. Dehydration sets in. And before they could do anything about it, Ishmael was near to death. He was already a teenager at this point, don't forget that. But the journey was apparently harder on him than it was his mother. And so when he could go no further, Hagar placed him in the shade and she went and she waited for him to die. Can you imagine the grief? Can you imagine the heartache? The pain she felt as she went, sat, and waited for the death of her boy. She went just far enough away so that she wouldn't have to watch. She sat down and in that moment of desperation she began to weep. She rose up her voice. She let out a great cry. And just as God had spoken to Hagar when she wandered in the wilderness of Genesis chapter 16, so too now he speaks to her again. Verses 17 and 18 say this, And God heard the voice of the boy, and the angel of God called to Hagar from heaven and said to her, What troubles you, Hagar? Do you think he didn't know the answer to that? No, he's penetrating the scene so that she might consider what was happening to her. What troubles you? Fear not, for God has heard the voice of the boy where he is. Lift up the boy, hold him fast with your hand, for I will make him into a great nation. If you pay careful attention to what we just read, you'll notice something a little unexpected. Hagar lifts up her voice, and God hears who? The boy. She lifts up her voice, and He hears the voice of the boy. Now that's maybe strange, but I think it makes sense when you recall that God's promises of preservation are particularly directed towards who? Ishmael. He is the one who is to be made into a great nation. So God responds to his cries of desperation. And then he comforts Hagar and instructs Hagar to help him. And then he provides the material means to sustain his life. Hagar had not seen it before. Maybe it was hidden. Maybe it was concealed. Maybe in her weariness she simply didn't have her head on straight. But there was a well nearby. And God now opens her eyes so that she might find it and get water for Ishmael and he might live. This was exactly what they needed to survive and God had provided. And therefore we're told that God was with the boy and he grew up. And he would grow up, be a man, he would learn to thrive in the wilderness. This would become his home. He would figure out how to make it. He would become a skilled bow hunter. And he would marry a woman from Egypt that he might have kids of his own. We see then that in the rivalry between Isaac and Ishmael, Isaac was the real winner. He would be the son of promise. And in order for him to fulfill that destiny, the son of slavery needed to be cast out. God would not forget the son of slavery. He would provide for him. He would make him a people too. But the fate of the two boys would be very different, as Isaac got the upper hand in the areas that mattered most. From henceforth, Ishmael would be on his own path, despite the fact that, as we'll see in a few chapters, he would eventually rejoin Isaac at the burial of their father. Nevertheless, Isaac alone would be Abraham's heir. That's the story of this famed, iconic rivalry as told by Moses in the book of Genesis. And with the details of that story before us, we can now consider this rivalry from a second angle. We want to think about this rivalry as interpreted by the Apostle Paul. Sometimes when we read these Old Testament texts, we have to really think about what doctrinal implications they might hold. But, in this case, the Apostle really draws those implications out for us on a couple of occasions. The first place that I want to direct your attention is to Romans 9, where Paul alludes to this story to help his readers understand what? To help his readers understand God's sovereign administration of the covenant and its blessings. At the beginning of Romans chapter 9, Paul is lamenting the faithless condition of his kinsmen according to the flesh, the Jews. As sons of Abraham, they had a great spiritual legacy, which they would have done well to have taken hold of. But we know that many of them had rejected the fulfillment of this spiritual legacy in Christ. showing that their connection to Abraham was like Ishmael's connection to Abraham. It was merely biological. And in making this point, Paul here, you'll look in vain for Ishmael's name there, but he doesn't mention Ishmael directly, but he alludes to him signing the principle which is first laid down in Genesis chapter 21. In Romans chapter 9 verse 7 he says this, Not all are children of Abraham because they were his offspring, but through Isaac shall your offspring be named. This means that it's not the children of the flesh who are counted as children of God, but the children of the promise. So in the eyes of the Apostle Paul, Ishmael and Isaac serve as representatives for those who had a fleshly connection to Abraham and a spiritual connection to Abraham, respectively. Ishmael for the fleshly, Isaac for the spiritual. Those who had rejected Christ were like Ishmael. They were not children of promise and thus they rejected the fulfillment of that promise in the Messiah. On the other hand, those who possessed faith, as had their forefather Abraham, they were like Isaac. They were children of the promise, receiving all that had been promised in the covenant through Jesus. Just like he did way back in Genesis chapter 1, God chose to sovereignly distinguish between ethnic Israel and spiritual Israel, granting the blessing of salvation to the latter, to spiritual Israel. And it's this sort of distinction which is present in a more nuanced way in Galatians chapter 4, which we read. In Romans 9, Ishmael and Isaac are a historical example of the way in which God sovereignly deals with natural children of Abraham and spiritual children of Abraham. But in Galatians, Paul goes a step further. And he uses these two boys along with their mothers as representatives of two principles pertaining to two covenants. The boys and their mothers, they become the faces of two basic groups into which everyone can be sorted. I should offer a disclaimer here that Galatians 4.21-31 is a difficult text. To really plumb the depths, we would need to spend time working through that passage in its own right. But rather than working through all of the intricacies of Paul's argument, I hope that having read it, you will accept a somewhat simple summary of what he says. Generally speaking, in Galatians chapter 4, Paul is addressing those Christians in Galatia who were listening to the Judaizers, and thereby putting themselves back under the law of Moses. And to those participating in this error, Paul draws upon, as he says, the law itself. Here he's referring to the law as the five books of Moses, Genesis through Deuteronomy. And he draws upon this portion of the law to demonstrate their folly. If they had faithfully and carefully read Moses, they would recall the story of Abraham's two sons, and they would understand the implications. So he reminds them of this. One son was born of a slave named Hegel when Abraham sought to provide himself a son through the deeds of the flesh. The other son was born of the free woman Sarah through the promise of God. These mothers and their sons, says Paul, allegorically stand for two different covenants and two different ways of relating to God. Now by saying that he's interpreting allegorically, he's not saying that the events of Genesis chapter 1 didn't actually happen. He's simply seeking to unveil a deeper theological significance to this. And so what is that theological significance? Well, he says that Hagar, who is so frequently in these stories wandering the wilderness near Arabia, he says, Hagar stands for Mount Sinai in Arabia. And she stands for the works principle attached to the Old Covenant. Consequently, she also stood for the earthly Jerusalem, the household of God's people under the law, including the Judaizers who were afflicting the church in Galatia. On the flip side, Sarah stands for the heavenly Jerusalem. the dwelling place of God's church, saved by grace through faith. She bore a child of promise and thus represents the gracious promises of the new covenant in Christ. Now if you follow that, this means that in the context of Galatia, where people were placing themselves back under the Law of Moses, they needed to think carefully about which mother and son duo they were associating themselves with. Would they be associated with Sarah, and Isaac, and the Promises? Or would they be associated with Hagar, and Ishmael, and slavery? Here's how Philip Reichert in his commentary sums up Paul's overall argument. He says this, The allegory shows the difference between spiritual slavery and spiritual freedom. Those who try to justify themselves by keeping the law are the slave children of Hagar, but those who are justified by faith in Christ are God's free sons and daughters. Two categories, two principles, Two covenants into which everyone can be sorted. Hagar, Ishmael, works, sin, slavery, Sarah, Isaac, grace, faith, promise, Christ. Everybody falls in one or the other. And therefore Paul, led with the church to understand the implications of their new identity in Christ. He says in Galatians 4.28 through 5.1, we'll read it, Now you brothers, like Isaac, are children of promise. But just as at that time he who was born according to the flesh persecuted him who was born according to the spirit, so also it is now. He's talking about the Judaizers persecuting the church. But what does the scripture say? cast out the slave woman and her son. For the son of the slave woman shall not inherit with the son of the free woman." They were to have nothing to do with the heresy of the Judaizers. They were to push that out. Why? Well, he concludes here saying, So brothers, we are not children of the slave woman, but of the free woman. For freedom Christ has set us free. Stand firm therefore and do not submit again to a yoke of slavery. You see, as Paul interprets this rivalry, Isaac and Ishmael point to the distinction between Abraham's natural children and his spiritual children. That's what we saw in Romans. And he demonstrates that in the eyes of God, we are all one or the other. That's his point in Galatians. Those who trust in themselves rather than in the finished work of Christ are children of slavery, like Ishmael. Those who trust Christ for the forgiveness of sins are children of promise. And those who have once experienced such forgiveness and such freedom as children of promise should never be tempted to wander down into the wilderness with Hagar and her son again. Freedom Christ has set us free. And that naturally brings us to the third angle that we want to come at this rivalry from, which is the rivalry as relevant to us. Having seen how Paul interprets these figures, Riken again incisively poses the question which we all must answer in response to Genesis chapter 21. He asks it this way, to which of these two Do you belong? To which of these two do you belong? In many ways, God had blessed Ishmael. He would have earthly success. God's promised that you'll be not just a nation, but a great nation. He would have children, and we're later going to get a genealogy of Ishmael. These children would go on to make up a nation indeed, and Ishmael's name would go down in history. These were kindnesses from God. God was with him and the boy grew. And these were kindnesses from God which might tempt any of us. But at the end of the day, God's plans for Ishmael only ran so far. He was still the son conceived by Abraham when he was trying to do things on his own. And as a result, he was the perpetual and consummate son of slavery. One day Ishmael would die. And Ishmael's children would die, and they would come under judgment because they did not receive God's covenant blessing by faith. They did not receive the promises. They did not inherit the covenant first announced in Genesis 12, ratified in Genesis 15, and confirmed in Genesis 17. Ishmael, though he had received the sign of the covenant, though he had been circumcised, he would not take hold of the substance of the covenant, my believing, he would be cast out, and therefore his success would be temporary. Isaac, however, would be blessed by God with both earthly blessings and heavenly blessings. He would have a relationship with the God of his father, becoming the sole inheritor among Abraham's offspring. When the slave woman and the slave boy were cast out, he would be the only one left standing. And so, while he was a sinner like his brother, Isaac would walk by faith all the days of his life, gaining an inheritance according to the covenant which would carry him from this life into the life to come. The gracious salvation purchased by Christ would be his. Though Christ had not yet come, the cause, what? He took hold of the promise. He believed. And brothers and sisters, with that said, the relevance of this age-old rivalry ought to be coming into view. In light of all that we've seen thus far, the pressing question which you must ask yourself is this. Which side of the rivalry am I on? Am I bound to Hagar and her slave son? Am I a fleshly person, a worldly person, living in slavery to sin? Are all of my hopes set on earthly riches? Is my life in this world as good as it's going to get? Do I lack a meaningful relationship to God? Maybe you've even received the covenant sign of baptism. Ishmael had two. Have you taken hold of the substance of the promises which it communicates? Or are you like Ishmael, you've only received the sign, but not the substance? Or on the other hand, are you bound to Sarah and Isaac? Ask yourself, do I have faith in Christ, the descendant of Isaac? Through whom all the covenant promises of God are yes and amen. Are my hopes bound up not on this earth, but with the glory of the Jerusalem above. Is Jesus my priceless treasure? Have I been justified and reconciled to God through faith in the one who died on the cross and defeated death by raising from the grave? I hope it's obvious which side of the rival you want to be on. You must not side with Ishmael, setting your hopes on something other than the gracious promise of salvation. That is a life of slavery, both now and forevermore. The son of the slave woman shall be cast out. So instead, you must take hold of the promise of redemption and blessing and the covenant of grace given to the saints of old and brought to fruition in Christ. Your faith must be in Christ. The one who stood behind all of the promises given to Abraham. The one who stood behind all of the promises given to Isaac and to Jacob and the tribes of Israel. Your faith must be in Him. And that means a few things. That means you must know about Christ and His work. You must believe that what the Bible says about Him is true. And you must trust that only He can save you from your sins. It's what faith requires. And with that sort of faith, you can be justified. In other words, what do we mean when we say justified? It's good to remind ourselves of these things at times. In other words, your sins can be pardoned, and you can be accepted as righteous in God's sight, for Jesus' sake, through faith alone. And when you have been set free from slavery to sin and justified in this way, then you come to know real, lasting spiritual blessing. You take hold of the promise which Isaac inherited. As children of promise, through faith in Christ, your chains are gone. Your guilt melts away. You know true riches and true joy. All that was promised to Abraham and more is yours. Not because you've earned it according to the deeds of the flesh. It didn't work out for Ishmael. But because Christ has earned it for you. And he has given it to you on the basis of his gracious promise. So the call of Genesis 21 is to flee from your sin and the slavery which comes along with it, setting your hope on the ultimate son of promise, the one in whom all the promises are fulfilled, Jesus Christ, himself the hope of Abraham and Isaac. For as God said to Abraham, through Isaac shall your offspring be named. And therefore, just as Abraham did so long ago, And as the Galatian church had to do many years after, we must heed the words of Galatians 4.30, cast out the slave woman and her son, for the son of the slave woman shall not inherit with the son of the free woman. We must cast ourselves upon the promise and become children of promise through faith in the Lord Jesus Christ. Let's pray.