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The Son of Promise

The Promises of God (The Life of Abraham)

Part XIV

Series: Genesis: The Foundations of the Faith

Sermon by J. Ligon Duncan on Apr 25, 1999

Genesis 21:1-21

Genesis 21:1-21

The Son of Promise

If you have your Bibles I'd invite you to turn with me to Genesis, chapter 21. A great suspense has been building ever since we heard the announcement in Genesis 12 that the Lord was going to fulfill His promises to Abraham by making Him a father. The father of many nations. And our hopes were momentarily gotten up when the birth of Ishmael came, but it was quickly apparent that this was not God's plan for the extension of His covenant family, and so we have been waiting patiently for almost ten chapters and for a quarter of a century. And perhaps it feels like it as we move slowly through these chapters of Genesis. Perhaps you've gotten a taste of the suspense even in the time that we have slowly moved through these passages.

But tonight we turn to Genesis 21, verses 1 through 21, where our suspense finally gets some relief. And so let's hear the word of the living God here in Genesis 21:

Genesis 21:1-21

Father, this is Your word, and we praise You for it. We praise You for your faithfulness to Your promises. We praise You as well for the glorious way that You establish our faith and Your covenant. We ask that as we consider these things tonight You would by the Spirit apply these truths to our own hearts, and our own situations for Your glory and our good. We ask it in Jesus' name, Amen.

Genesis 21 comes as a welcome relief. Over these last few chapters we have covered some of the saddest chapters in all of this Book indeed and all of the holy scripture. And when we come to Genesis 21 we're told about the birth of Isaac. A birth that we have been waiting for for many chapters. A birth that Abraham and Sarah had been waiting for for many years. And his name itself indicates it means laughter. And we sense the joy in the birth of this son. This was the miraculous birth long before promised by God.

But Moses also tells us in this chapter of the dissention that grew up in Abraham's family that led to a very painful parting of the ways. But that dissention which led to that parting of the ways to that division is very significant for the covenant of grace. And so I'd like to look at these two things with you tonight here in Genesis 21. The chapter divides easily into two parts, the first seven verses, 1 through 7, deal with this birth of Isaac and then from 8 to 21 we see the expulsion of Hagar and of Ishmael from Abraham's tents and they go their own way. Let's look at these two sections together.

I. God keeps His word.

First, at verses 1 through 7. We learn a very simple, but very important message here in these verses. God keeps His word. In this passage the long wait comes to an end and finally the birth of Isaac arrives, and we are immediately struck with the emphasis on the fulfillment of God's word in verses 1 and 2. Three things I'd like you to see there in verses 1 and 2.

First of all notice that it is made clear that the Lord's providence, His kind and good providence was upon Sarah. Despite everything that it may have looked like to those around Sarah, it might have looked like the Lord was against Sarah. She had no children of her own. She had been frustrated and ridiculed in her own house by her own maid servant, and yet the Lord's kind providence was upon Sarah. Look at verse 1. "The Lord took note of Sarah." And then especially these words, "as He had said." He had promised Sarah that His heart was upon her and just like He had said He fulfills His promises.

But He's not finished. Look at the end of verse 1. Then God gives Sarah a son, just like He had said. Look at the phrase. "The Lord did for Sarah as He had promised." The Lord's word is fulfilled. And then look at verse 2. At the end of that verse it's not only stressed that the Lord had given her a son, but He gave her a son just when He said He was going to give her a son. At the appointed time of which God had spoken to him, that is to Abraham. And so three times in the first two verses, it is stressed that God's promises, God's words were fulfilled in the actions that He did on Sarah and Abraham's behalf. You see what God says is reality because God's word rings reality into being. And therefore His promises are inviolable, and it is impossible that He should not be faithful to that which He says. Because what He says brings into being that which is not. You remember the Genesis account of the creation of the world. "And God said and there was." And His promises are no different than His creation. So there is a glorious stress on the fulfillment of God's word here in this passage.

Furthermore, the very name given to the son, Isaac, illustrates how the Lord has turned around the reproach of Abraham and Sarah, and He has turned it into a matter of blessings. Isaac, the name which means laughter is accompanied by this phrase. If you look in verse 6, "God has made laughter for me and everyone who hears will laugh with me." Once upon a time the only laughter heard in the tents of Abraham and Sarah about their offspring was laughter against them. No doubt Sarah herself had felt many days of reproach. But now that laughter is only joy and those who laugh, laugh with her at God's kind providence. The Lord has turned a reproach into a blessing, and it's marked in the very name of the son which no longer conveys a mocking derision, that kind of laughter which is biting, but which conveys joy. And Sarah, too, is vindicated. She says it herself. Look again there in verse 7. Who would have said to Abraham that Sarah would nurse children. Yet I have born him a son in his old age. The Lord has been kind to practical Sarah as she has waited over many, many years.

What's the application of this truth. It's very straightforward isn't it? What God says is reality, and therefore it is impossible that He will not keep His word. And so we can and we ought to trust Him. All of us tonight have our own challenges in trusting the Lord. But the Lord's reminder to us in the story of Abraham and Sarah and Isaac is a reminder that He can be trusted, because His word brings about the reality of which it speaks. One old Christian has said believing prayer takes its stand upon the faithfulness of God. If we do not believe that God is faithful, then it will be very difficult for us to lift up believing prayer. And so even as Abraham and Sarah rejoice at the birth of a son, we cannot help but see in this passage them rejoicing in something prior to the birth of that son, and that is the promise of God that that son would be born in the first place. And so surely this is a spiritual joy that is rejoicing in the faithfulness of God to them for He has done just as He promised. Spurgeon says, "The more we study the words of grace, the more grace we derive from the words." So if we're having a struggle tonight trusting in God's goodness and faithfulness, then maybe we need to do what Spurgeon has suggested and study again the words of grace. Rehearse the promises of God to us; meditate on them; dwell on them; remember His faithfulness; and then determine by God's grace to trust Him at His word. God keeps His word. And at long last we see the fulfillment of that word here in verses 1 through 7.

II. God's electing love will separate us from the things of the world.

And then something hard happens on the heels of this very happy event. If you look at verses 8 through 21, you see a conflict which re-enters into the family life of Abraham. Once again Hagar leaves. This time she is expelled along with Ishmael. And this time it is for good. And we see here even in this painful chapter in Abraham's life that God's electing love separates us from the world. God's electing love will not allow our hearts to be intertwined with the things of the world. And no matter how dear they are to us, the Lord will take them and pluck them from our breast, because His electing love wants us for Himself.

For years there had been discord in Abraham's family, and yet for fourteen years since the birth of Ishmael and the first flight of Hagar and Ishmael there had been some manner of peace in the household of Abraham. They had managed to stay together. But with the birth of Isaac, tensions were at a new high. You can understand why. Ishmael now was a teenager, fourteen years old or so. He was old enough to know that he was slated to be the heir of Abraham. And when a son came by Abraham and Sarah, Ishmael immediately knew that he will have been displaced as the heir of Abraham. And the resentment apparently builds. A great feast given for Isaac on the time of his weaning. And we are told in ancient cultures weaning was occurred much later. He was perhaps three years old when he was weaned. And at a feast given at the time of the weaning of Isaac, the pressure becomes unbearable. And Sarah sees Ishmael, mocking, not merely playing or teasing, but ridiculing, maliciously mocking little Isaac. Erdman explains why this would have happened. He says, "The prospects and expectations of Ishmael are suddenly shattered. He had grown to youthful vigor, confident that he was to inherit great wealth, and the power of his father. Now the true heir appears. Ishmael is moved to mad hatred. Proud and impetuous, he does not conceal his chagrin. On the occasion of a great feast given in honor of Isaac, he is guilty of insolence, and mockery and insult." And Sarah sees it. And so Sarah immediately demands that Abraham drive out Hagar and Ishmael from the midst. And as she does so, she utters some very important words. She says, "The son of this maid shall not be an heir with my son, Isaac."

Now the Scripture tells us that those words are not merely the words of an angry woman whose child has been hurt and ridiculed, but those are actually the words of God indicating the difference between Isaac and Ishmael. And I want to remind you of this in two places. One in the Old Testament, one in the New. Turn with me first to Psalm 83. The 83rd Psalm indicates that the division between Isaac and Ishmael was not nearly one that resulted from a family squabble. There was a deeper spiritual significance to this division. In Psalm 83, verses 5 and 6, we are told about nations related to Israel which are yet set over against Israel in conflict. Pick up in verse 4. "They have said, ‘Come and let us wipe them out as a nation.’" These are the other nations saying this about Israel. "‘That the name of Israel be remembered no more.’ For they have conspired together with one mind against Thee do they make a covenant the tents of Edom and the Ishmaelites. Moab and the Hagarites." So here we see the descendants of Ishmael in opposition to Israel determined to bring about the end of that nation. So even in the Old Testament the distinction between Isaac and Ishmael is more than simply an accident of history. It is vested with great spiritual significance.

But Paul heightens this for us. If you’ll turn with me to Galatians, chapter 4, you’ll see this. We’ll simply zero in on verses 28 to the end of the chapter. In Galatians, chapter 4, Paul draws a line from Ishmael to the unbelieving synagogue of the time of Christ and the apostles and he draws a line from Isaac to the heavenly Jerusalem which is the kingdom of God. And he says this in Galatians 4, beginning in verse 28: "And you brethren, like Isaac, are children of promise. But as at that time he who was born according to the flesh persecuted him who was born according to the spirit, so it is now also." Paul was saying ,don't be surprised if the synagogue is persecuting you. Ishmael persecuted Isaac. Don't be surprised if the unbelieving seed of Abraham is persecuting you, the unbelieving seed of Abraham persecuted Isaac persecuted Isaac. There's Paul's argument. But he continues. "But what does the Scripture say?" And notice that Paul doesn't say but what does Sarah say? He says, "But what does the Scripture say? Cast out the bondwoman and her son, for the son of the bondwoman shall not be an heir with the son of the free woman.’ So then brethren, we are not children of a bondwoman, but of the free woman."

Now I simply want to point one thing out about this passage. It is clear that when Sarah asked Abraham to cast out Hagar and Ishmael she was asking him to break the current law. Current law in Abraham's time, at least current custom, did not allow a slave, a maid servant and son of the household to be turned out without any provision. And yet Sarah was asking Abraham to do that. Now whether she was doing that in momentary spite, it doesn't matter. What Paul is telling us is that God used that statement of Sarah to indicate a very important spiritual reality. For even if Sarah's motives were not entirely pure, God had a perfect reason for what He was doing. In fact, He instructs Abraham later on to listen to what Sarah said because God is using Sarah as His instrument. This is not the first or the last time in the book of Genesis that we will see the action of a human being which is wrong, stated to be part of the plan of God, which is right and good. Think of Genesis 50:20. "You meant it for evil, but God meant it for good." And once again even if Sarah is wrong in her desires here, her words are, according to Paul, the very words of God expressing a distinctive destiny for Isaac and for his descendants in the covenant of grace. And so we see that this distinction between Ishmael and Isaac is more than just a family squabble, it's a distinction between the natural and the spiritual seeds. And did not God promise through Moses and did not God promise through the record of Moses and in His words to Adam, that He would put enmity between the seed of the woman and the seed of the serpent? And we're seeing yet another incidence in the book of Genesis where God establishes enmity in order to bless His people right here.

Now let's turn back then to Genesis 21. Sarah has asked Abraham to cast out Hagar and Ishmael and Abraham is deeply distressed. This is perfectly understandable. Ishmael is probably seventeen years old now. We have seen indications all along that Abraham loved this boy deeply. In fact, when God came to Abraham to promise him the birth of Isaac, do you remember Abraham's response? Oh, that Ishmael might live before you. In effect, oh, that Ishmael might be the heir of the covenant. Abraham loved this boy. Sarah was asking Abraham to cast out his son and never see him again. That parting and the thought of that parting must have been brutal to Abraham. You know, of all the scenes that reduced me to a puddle in this last week in Littleton, Colorado, there was the scene of that school teacher as he lay dying. And his students pulling out his wallet to show him the picture of his girls. And his final words, "Tell them that I love them." And here Abraham must send out a boy that he loves and never see him again - into the wilderness, into the desert heat, perhaps to die, never to be reunited. Do you feel the cost of this parting to Abraham. However Sarah feels about Ishmael and Hagar right now, Abraham loves that boy. And so Abraham is quite understandably distressed. Not only does law prevent him from turning out Ishmael without a provision, but his love for his son breaks his heart at the thought of losing him. And so God himself comes to Abraham and He says, and this is so beautiful, Abraham, I will provide for your boy. I know it's hard for you to understand what Sarah is saying to you right now, but what Sarah is saying to you is part of my plan. So I want you to listen to her and I just want you to know this. I will provide for your boy. Because I love you, Abraham, I will make him a great nation. I will protect him. And so you do what Sarah has asked you to do, however brutal it seems, however heartbreaking it may be to you.

And Paul of course uses this incident of the division of Abraham's son, Ishmael, from Isaac and his family to explain the stumbling of Israel in his own day and also to explain his doctrine of election. Turn with me to Romans 9. There in Romans 9 Paul quotes from words we have just read in our own passage in Genesis 21. Look at Romans 9 and we begin in verse 6. Paul says this: "But it is not as though the word of God has failed." What's Paul speaking about? He's speaking about the fact that so many Jews have rejected the Messiah, and the question has come to him. Does that mean that God's promises have failed? God indeed made the covenant of grace with Abraham and his descendants after him. Does this mean the fact that so many Jews have rejected Jesus Christ, have rejected the gospel message, does that mean that God's promises have failed? That's the question of the apostle Paul and his words in verse 6, "It is not as though the word of God has failed. For they are not all Israel who are descended from Israel."

Paul immediately states a very important principle. Not everyone who is physically Israel is part of spiritual Israel. Not everyone who is descended physically in the flesh from Israel is part of the spiritual kingdom of Israel. And he goes on and he gives a specific Old Testament example. He says, "Nor are they all children because they are Abraham's descendants, but through Isaac your descendants will be named." Those are the words that God spoke to Abraham when He assured him that he needed to follow through on Sarah's request and turn out Ishmael. Why? Because Abraham, through Isaac, your descendants will be named.

So Paul goes on to explain in verse 8. That is, it is not the children of the flesh who are children of God but the children of the promise are regarded as descendants. "For this is the word of promise: At this time I will come and Sarah shall have a son." Do you see what Paul is saying? He's saying look, Ishmael and Isaac were equally children of Abraham's flesh, but one was the son of promise, Isaac. The promise was given and about this time I will give you a son. That was a promise for Isaac and that was not given of Ishmael. So Paul is indicating a fundamental distinction in the plan of God and the covenant of grace between Isaac and Ishmael. God has set His heart and His covenant on Isaac and not on Ishmael.

I want you to pause and think for a moment. Even so, God is kinder to Ishmael than Sarah is. And so often we think we are kinder than God. We can't believe that God would choose some and not others. We think, you know, I'm a lot kinder than God. If I were God I'd choose everybody. But this passage makes it very clear that Sarah is not kinder than God. God's kindness far eclipses hers. And so Hagar and Ishmael make their way out into the wilderness in Genesis 21:14. By the way, critics used to make fun of this passage and say there's clearly a mistake in this passage because in verse 14 it says that Hagar carried Ishmael. And there's a word used, that Abraham puts the wine sack or water sack or the wine skin on her back, and also gives her the boy. And the critics say, you see that's saying that he gives her the boy into her arms. But it's very clear that what's being spoken of in verse 14 and following is not Hagar carrying seventeen year old Ishmael as a baby. But as they get out into the wilderness, her shouldering him, half supporting and half dragging him until he finally collapses and she puts him under the bush cover. And the story closes, of course, with God providing for Hagar and Ishmael, just as He had promised to Abraham, and also giving one of those secular blessings that we see in the book of Genesis to Ishmael. Promises to make him a great nation, but there is no promise in the passage to be his God, though we are told that the Lord was with the lad.

What do we learn from this passage? Just as God had separated Abraham and Lot, now he has separated Abraham and Ishmael that his heart would be wholly God's. You see ,the loss of Ishmael forces Abraham to stop hedging his bets with regard to the promises of God, and sets us up for the scene that will take place in Genesis 22. When Genesis 22 arrives and Abraham is climbing the steps of Moriah there is no other son to fall back on. That son is gone. God has cleared him out of the way so that Abraham's faith must be built up in the very trial of fire by trusting the whole of his hopes into the hands of God. And Hebrews 11 makes this very clear. Turn with me there. In Hebrews 11, beginning in verse 17, we read: "By faith Abraham when he was tested offered up Isaac and he who had received the promises was offering up his only begotten son. It was he to whom it was said, ‘In Isaac your descendants shall be called.’" Do you hear the echoes of those words? Once again, "In Isaac your descendants shall be called." He considered that God is able to raise men even from the dead from which He also received him back.

In other words, Abraham in that circumstance could not fall back in his mind and think, well, maybe God is going to take Isaac from me and Ishmael will be the heir. There was no Ishmael anymore for Abraham. If God was going to establish His seed, it was going to be through Isaac and through Isaac alone. So the loss of Ishmael makes that scene in Genesis all the more poignant, but it is the instrument that God uses to build up Abraham's faith. As it was, He breaks his heart in order to build up his faith. Because God loves us he draws our hearts away from anything that might separate us from Him or compromise our trust in the promises of His covenant of grace.

Perhaps there's something like that in your experience right now. Some hope, some dream, some prayer and the Lord doesn't provide this. And you think that the Lord is withholding something good from you. It may be that just as in the case of Abraham and Ishmael, the Lord is rather preparing you for blessing and building up your faith. May we trust until we see the light. Let's pray.

Our Lord and our God there is nothing so hard as to walk by faith when there is no sight. But there is nothing more glorious than to trust in You despite all the evidence to the contrary. Give us the faith of Abraham that we may trust in Christ. We ask it in Jesus' name, Amen.

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