The Birth of Isaac

[0:00] trust. And really the big takeaway then, I suppose, for us is what does it look like for us to trust in God's promises? As well, why would we want to do that? And ultimately, how can we do that more? How can these verses encourage us to live as his people, trusting in him? And I think it's worth saying as we begin, just a big kind of picture reminder, it's good to keep in our minds that everybody trusts in something, that everybody is building their life on something.

[0:37] In our world, so often it's presented as if Christians or religious people have a faith, and everyone else has no faith. Everyone else is simply a blank slate or completely neutral.

[0:50] But the reality is that we all have faith in something. If you're here this morning and you're not a Christian, or for our colleagues and friends who aren't Christians, even for Christians, when we struggle with our faith, which is not an uncommon experience, the reality is that at those times, or those people we know who don't trust in the Lord, are not trusting in nothing.

[1:17] But ultimately, it's trusting in something else. Perhaps it's our finances, perhaps it's our family, perhaps it's our health. But all of us have one of any number of things, where we think, well, so long as I have this, it will see me through. So long as this is in place, then I'll be okay.

[1:38] And so as we work through the life of Abraham, we're looking to see why actually trusting in God is better than any other alternative. Not that those things are necessarily wrong or bad things, but that there is an issue when they are our ultimate foundation. But trusting in God is better.

[1:55] And we're going to see as well what that looks like. Again, whether that is needing to put our faith in God and his promises for the first time, that might be something that some people here need to do this morning, or whether that is to keep on living as his people by faith, day by day.

[2:14] And this is a great passage where we see, as we're looking to do that, we see that we are trusting in a God who keeps his promise. We see this morning the birth of Isaac, the long-awaited son on whom everything depends for Abraham and Sarah. In these verses, promise becomes reality for them as God shows his faithfulness. God shows he is the one who is worth putting everything on. And we come to see that he is the God who can be trusted. And we see how his faithfulness works itself out in our world. And we're going to look at that three aspects of that that we see in the life of Abraham and Sarah in chapter 21. And that remained true for us today as we look to live as God's people. And the first thing is this, that God's faithfulness to his promise brings blessing and joy. And really the kind of first emphasis of this passage that runs throughout the whole section, but to underline at the very beginning, is that God is faithful to his promises. That is what's being underscored in verses 1 and 2. Let me read them again and notice how God doing what he'd promised is repeatedly highlighted in these couple of verses. It says,

[3:38] God doing as he has said he will do. And even down in verse 7, where Sarah asks, who would have said to Abraham, that Sarah would nurse children? And yet we remember, well, that's exactly what God had said to Abraham. And we see in these verses that that is what God has done. God does as he says he'll do.

[4:18] God is faithful to his promise. The focus is on God. And it says we focus on God. That is how we come to be people who trust more in him. C.S. Lewis has a famous passage giving advice to would-be authors where he tells them, basically, don't tell people how to feel, rather make them feel it. He says, instead of telling us a thing was terrible, describe it so we'll be terrified. Don't say it was delightful.

[4:51] Make us say delightful when we read the description. In some ways, that's what's happening here in the Bible. We're not simply told, have faith in God. But we are shown that God is faithful.

[5:05] We're not simply told, stick with God. Rather, we are shown that God will not forget his promises. It is the Bible's description of God and what he is like. It is looking to this faithful God who proves that faithfulness through his actions that enables us to have and to deepen our faith in him. And we see here that as God shows his faithfulness, that it brings blessing and joy.

[5:39] Sarah has been through incredible hardship in the chapters we've worked through. She has so far not been able to have this child that she was promised and she so desperately desired. This child that would have been the sign of God's presence and blessing on her to this point that's been withheld. And we've seen how at times that has left Sarah bitter. That at times that has left her doubting. But now we see as God fulfills his promise, it brings her this great joy. Verse 6, Sarah says, God has made laughter for me.

[6:16] Everyone who hears will laugh over me. God's faithfulness brings Sarah joy. And also we see that that joy spreads as well to others. The very name, in fact, Isaac, it means he laughs. That idea of blessing and joy that will come through this son is kind of writ over the whole of this event.

[6:40] And as we bring this forward to the church today, as we trust in the same God, the encouragement is that we're able to trust in this same faithfulness. Ultimately, as we've been seeing through these chapters, in the same promises that bring blessing and joy to us as well. Remember the promise to Abraham that through him, all the nations down through the generations would be blessed. That's what God had promised. And because Isaac is the son through whom ultimately many generations later, Jesus, the fulfillment of that blessing was born. We've seen how if we're to turn to the very beginning of the New Testament, the opening verses of Matthew's gospel give us that genealogy.

[7:29] Abraham there as the first name, Isaac as the second, running right through to Jesus Christ. The point is that we are brought into this blessing and joy, that we are able to be brought into this laughter that we see here in Genesis chapter 21 because of God's same faithfulness to his same promise, which is fulfilled in Jesus. And I love that we see that at this part in Genesis because the last really nine chapters of Genesis have shown us what the journey to that joy often looks like, particularly that it can involve waiting. I think we've mentioned this before, but it is now 25 years since Genesis chapter 12 and God making his first promise to Abraham. I've got a kind of mental exercise for you. Cast your mind back and think what you were doing 25 years ago. For some people, that would be difficult because you weren't born. That makes it harder. For the rest of us, it was the year 2000, you know, the new millennium. You probably had a terrible haircut and embarrassing clothes and things like that. That's okay. It's a long time ago, a significant proportion of our life. That is how long Abraham and Sarah had been waiting for this fulfillment, for this joy, for this blessing.

[8:59] It can be so easy again for us to come to church or for me just to stand at the front and say, let's just trust God. And yet it's so important. We see from the Bible, that doesn't mean that we get everything here and now. It is hard to keep trusting God over the long haul. That's what we've seen through these chapters. God has kept his promise through Jesus. The promised rescuer has come, but we are still in a time of waiting for Jesus to return and for us to experience the fullness of that blessing and joy. When the pain of our world will be removed once and for all. When sin will be dealt with.

[9:41] When we'll be perfectly renewed. But God has promised he will do that. And God is faithful to his promises. Genesis 21 encourages us then to keep on trusting. Now that when we might think God has forgotten, he hasn't.

[10:00] John Calvin writes on these verses that God never feeds his people with empty promises. The point again that God will do as he's promised. He has initiated that through Jesus. He will bring that to its climax when Jesus returns. And we can hold on to that promise and his faithfulness to his promise in the meantime. Looking forward and knowing that that promise means ultimate blessing and joy.

[10:28] One thing I think as well that's helpful here before we move on is just that reminder to hold on to the promises that God has made rather than the promises that we might wish God had made. And so God has promised this eternal blessing and joy through Jesus that we are brought into his family for all eternity. That is God's promise. That is what we hold on to. Again, God hasn't promised us kind of smooth and easy in the meantime. We are able here and now to have laughter because we know what's in store and because God is kind to us in many ways here and now. But we also at this present time, we have tears that go along with that laughter. We have hardship. We have things in our lives which are not as we wish they were.

[11:18] Those things are not a sign that God is not faithful to his promises. Rather, they are encouraging us to keep on trusting in what God has promised of this eternal joy and blessing. Now, we said how everyone trusts in something. The good news is that if we're trusting in God's promises, that they hold fast through these difficult times that we face rather than crumbling under their weight. And they lead us forward to a certain future because we know the certain faithfulness of God to his promises. So God's faithfulness to his promise brings blessing and joy. Really, that's verses 1 to 7. And in some ways, if we just finish there, in some ways, this passage will be a lot simpler. We like speaking about blessing. We like speaking about joy. Those would be great things to go home thinking about. And it's really good that we do hold on to those. But also good that we see that this passage doesn't finish here and that we read on because we also see in this chapter that

[12:25] God's faithfulness to his promise brings separation. And we see this from verse 8 onwards. God's faithfulness to his promise brings separation. Now, let me kind of run quickly through this next part of the narrative.

[12:40] Isaac grows up to be aged two or three at this point. There's a great feast in his honor. That would have been quite normal practice at this time. But at this feast, Sarah sees Ishmael. Ishmael, the son of Abraham with Hagar, the slave girl. We learn all about that kind of messy situation back in chapter 16. Sarah sees Ishmael laughing. It says, verse 9. And if you have one of the blue church Bibles, you'll see there's a little footnote there. And down at the bottom, it says, possibly laughing in mockery. And I think most commentators would say that is the best understanding of what is happening here. Everywhere else, the form of that word for laughing is used in the Bible. It's used in this negative, this derogatory sense like that. And perhaps most significantly, when we turn to the New Testament, kind of God's divine commentary on the Old, speaking about this event, Paul says that Ishmael persecuted Isaac.

[13:45] So there's this idea of hostility there, of opposition that sets in. And the result is that Sarah wants Hagar and Ishmael sent away. Verse 10, cast out this slave woman and her son. For the son of this slave woman shall not be heir with my son Isaac. Now we see that Abraham is sad about that. Ishmael was his son.

[14:12] But really crucially, verse 12, we see that God seems to back up Sarah's decision. He says there, whatever Sarah says to you, do as she tells you. For through Isaac shall your offspring be named.

[14:30] I think we need to be really careful here, really deliberate here, to separate potentially Sarah's attitude and motivation from God's attitude and motivation, even though they both end up in some ways in the same place, with the same result of Hagar and Ishmael being sent away. I think there's a fairly strong argument, and lots of people have made this argument. I think I would agree with it, that Sarah's attitude here is not good. Again, a great aspect of the Bible is that it's really open about people's flaws, even God's people, even the people who are supposed to be the heroes. I think Sarah here may well be fueled by self-interest or anger. She is certainly not gracious toward Hagar and her son, while we'll see in just a moment how God shows real care to them. But whatever the motivation behind it, we see that actually Sarah's statement, the son of this slave woman shall not be heir with my son, we see that as a true statement, and we see that God affirms that it is through Isaac shall your offspring be named. It's through Isaac that this nation God has promised will come into being. It's through Isaac that ultimately God will bless all the nations, as he said. And as we've just remembered, that's ultimately because it's through Isaac that Jesus, the rescuer, Jesus, the source of this blessing will come. Again, we want to celebrate God's faithfulness to his promise, that through him there is blessing and joy found in Jesus. But through God's promise, there remains this separation, as it's only through Jesus that we can have access to this promised blessing. It's our response to Jesus that ultimately defines our identity. You might remember when we looked through the letter of 1 Peter last year, it spoke about Jesus as the cornerstone, either a rock of salvation or a rock of stumbling.

[16:38] And again, into the New Testament, Paul's letter to the Galatians picks up on this very moment in Genesis chapter 21, the sending away of Hagar and Ishmael, this separation. And again, Paul uses that as a picture to point to Jesus and the gospel. He says either we live a life trusting in other things, and Paul particularly in that passage speaks about trusting ultimately in ourselves. Either we can trust in our own efforts, we can trust in our own good works, we can trust in our own moral performance to get right with God, or we can trust in Jesus as the fulfillment of God's plan of rescue. We can trust in his perfect life lived for us, his sacrificial death, paying the penalty for our sins, his resurrection opening up the way to new and eternal life for us. The Bible is clear that it is one or the other.

[17:41] There is this separation, and God's fulfillment of his promise through Jesus is the dividing point. We can trace that right back here to Genesis chapter 21, that God's faithfulness to his promise produces a separation. And it's only through Jesus that people are brought in to be God's people and enjoy the blessing that he offers. As we think about this kind of side of God's faithfulness, this outworking of God's promise, it's really good to be kind of upfront and see that this is not a popular thing to say.

[18:17] We live in a world that is very suspicious of exclusive claims, particularly in terms of religion. When Jesus says, I am the way, the truth, and the life, no one comes to the Father except through me, really the kind of fulfillment of this separation. When Jesus says those words, he's speaking very differently from how our culture speaks, or how our culture would like us to speak about our faith.

[18:44] And yet throughout the Bible, God has been clear that the blessing he promises comes only through this line of promise, as it finds its fulfillment in Jesus. We'll come back in a moment to see how still that blessing is available to everyone. But first, it's great for us to take stock of this as a church, and it's a great reminder that we need to keep Jesus at the very heart of all that we do, because it's through Jesus alone that this blessing comes. The message that we need to hold out to people has to have Jesus at the very center of it. We want to show people kindness. We want to show people love. We want to serve our community and those around us. We have to do all of these things.

[19:31] These are important things of being God's people. But ultimately, we've got to get to Jesus, to his kindness, to his love, to his service, because he is the one who ultimately makes all of the difference.

[19:46] I read this recently. It really kind of struck a chord with me. I think this is true for those we speak to both inside the church and outside as well. The author said this, that people share their struggles, and with every good intention, others give good advice or try and step in to be the solution themselves. People do need answers. They are in need of help. But we fail to truly help them if we don't give them Jesus. He is the best answer and the most powerful help they can receive.

[20:22] Here is the separation that the blessing God brings is found in Jesus alone. He is the fulfillment of the line of promise. There is salvation nowhere else. Anything else we hope in will fall short. And so we want to make sure that Jesus remains at the heart of all that we do as a church, and that we don't simply welcome people in through Jesus and then kind of put him to one side as if we now get on to the practical stuff, and everything is programs and solutions and answers. But rather, we keep on pointing back to the gospel. Keep on pointing back to Jesus, because he is where that blessing is found, both to those outside of the church and also to one another. Jesus alone is where hope, where blessing, where help, where joy is found. And so we want to keep on connecting our lives. We want to keep on connecting the struggles of those who we know. We want to keep on connecting those around us with Jesus, because the gospel brings this separation. And it's only through him that we have access to all the good that God has promised. So God's faithfulness to his promise brings separation. But finally, if that's the kind of tough bit to hear, if we're worried that that sounds kind of restrictive or narrow, this idea of separation, we finish this passage by seeing that God's love is not at all narrow, that God's love is not at all restricted. Rather, thirdly and finally, we see God's faithfulness to his promise overflows. Despite this separation that happens, when we actually read through this passage, we're left in no doubt of God's care and God's concern for Hagar and Ishmael, that God does not cast them aside, but rather God keeps his promise to them as well. Back in chapter 16, we saw for the first time how tenderly God dealt with Hagar in her time of need. We saw how God made a promise to her as well. Chapter 16, verse 10, the angel of the Lord also said to her,

[22:44] I will surely multiply your offspring so that they cannot be numbered for multitude. And we see here that God hasn't forgotten this promise either. God affirms this promise to Abraham in verse 13 as he sends Hagar on her way. God affirms this promise to Hagar herself down in verse 18, when she's at the end of herself, and when she has given up and thinks that her life and the life of her son is over. And God keeps this promise by rescuing them, saving their lives, providing them with water, and not only that, by being with them as the boy grows up, it says. Now we see here God's faithfulness to his promise overflows as it is not just the line of promise that God shows care toward, that God gives good things to, and that God keeps his promises to. But he is abundant, he is overflowing with faithfulness. And so as we draw to a close, what do we do with this last section, this last point then? Because we said on the one hand there is a separation, and yet we're seeing here how God shows kindness to all. God keeps his promise to Hagar as well as to Abraham. So is there not really any difference at all? Well, I think the point is this, that God is kind to everyone. Ultimately, whatever they believe, whoever wakes up and feels the sun on their face, or anyone who has some experience of love and positive relationships, ultimately anyone who has breath in their lungs is experiencing

[24:30] God's kindness to them, as life itself is a gift from God, as he is the source of every blessing. Theologians would call this common grace, that you don't need to be a Christian to experience God's goodness to you, even if you don't recognize God as the source of that. But God gives gifts and abilities and wisdom to all people. God is a generous, God is a gracious God, and yet this is not the same grace as salvation. God is kind to all people. We all get more than we deserve. But we see this particular kindness of eternal rescue that only comes through Jesus, that line of promise and those who follow him and put their trust in him. And as we see God's overflowing goodness here, as that reveals something to us about God's character, I think ultimately the point is that that's to be an example to us as his church, as God's people on how we are to then treat others in light of God's faithfulness to his promises, particularly those not in the church, that we would see and we would act as God does. We live in a world which more and more builds up walls. More and more the idea is, are you with us or are you against us?

[25:56] Are you on our side, politically, nationally, religious beliefs, or are you one of them? And we look after our own and we demonize the other. But we see here that those who have faith in God and his promises should be modeling their lives on how he treats others. Now that we should show that same concern and kindness as God does to all those who are made in his image. And it's as we do that, that we are hopefully able to bring people to understand that the greatest love that there is, pointing them to Jesus and the promised blessing that is available through him. If our concern is the middle section of this passage, that God's faithfulness to his promise brings separation, if our concern is that that's exclusive and we feel anxious about things like that, well, the fact is that the Bible never waters that down. Jesus himself speaks most clearly about that.

[27:05] It is only him. It is exclusive in that way. And yet the Bible is also clear that the gospel is the most inclusive message of all because that invitation is there and is held out to all.

[27:20] And that everyone who turns to Jesus will be brought into the eternal blessing that he has brought. And it's the most inclusive message there is because it's not based on our performance.

[27:32] We don't have to do anything to earn his love. It's not about relying on anything else in the world, things that people may or may not have, things that people may lose, or things that people may have taken away from them. It's not based on things which are unpredictable and unstable and uncertain.

[27:53] But it's about having our trust in the promises of God, which are certain and which he has proved his faithfulness to. His promises fulfilled here in the birth of Isaac trace down that line to Jesus.

[28:07] Jesus, through whom we are all welcomed home, if our trust is in him. The great news of this passage is that the joy and blessing that comes through God's faithfulness to his promise is available to all people. It is available through Jesus. And so we want to keep him at the very heart of all that we are, all that we do, and all that we say. Let's pray together.

[28:31] Heavenly Father, we thank you for your faithfulness. We thank you that you don't just tell us to trust you, but that you have demonstrated time after time throughout history, that you have revealed in your word, that you are the God who can be trusted. We thank you for your promises which find their fulfillment in Jesus Christ, in whom is perfect blessing and joy for all eternity. For all those who turn away from their hopes of saving ourselves, who turn away from our putting our trust in our reliance elsewhere, and instead trust in Jesus and the gospel alone for our salvation, his death in our place, his resurrection, the seal of his victory. Lord, we thank you for your grace freely offered to those who humbly ask for the forgiveness that he alone provides. Lord, we ask that as we remember your faithfulness and as that moves us to lean on you, to put our trust on you more this week, that you would be with us in all of these things, that every step of our lives, every decision that we take, every moment we go through, you would be helping us more and more to live in light of the promises of

[29:54] God, that that would shape and define our actions in really practical ways, that we would do that boldly, that we would do that with confidence and joy, and that we would do that showing love to others, that they too might come to know your love for them. We ask that in every situation, including the hard times that we walk through, that you would be drawing our hearts to you, and through the work of your Holy Spirit, you would be helping us to live lives for your glory, confident in your faithfulness to your promises, fulfilled in Jesus Christ. In his name we pray. Amen.