As Paul has finished with the powerful metaphor of the false teachers seducing the Galatians away from Christ, now he moves to another powerful analogy found in the Old Testament, that of Ishmael and Isaac. This metaphor has particular power precisely because the people of Israel considered this story to be proof that God had chosen them over Ishmael. They were God's people through biological ancestry. However, Paul is going to turn this on its head as he turns it into an allegory-allegory is the actual Greek word translated in verse 24 as, "figuratively," "symbolically," and "illustration."
This highlights the reality that the life of the patriarchs and the events of them were often illustrations or allegories of things that God was going to do in the future. The events were real but God allowed them and even orchestrated parts of them because they had deeper significance that pointed to things God would do in the future. An example of this is when Abraham is told to sacrifice Isaac. It is clear God never intended for Abraham to sacrifice his child. But the whole event is an allegory depicting the heart of God that would one day sacrifice his willing child as the lamb of sacrifice for the sins of the world and in fact in the very place tht Abraham did it. You could say that through Abraham, God put the spirit world on notice of what he intended to do in that place. So that late when it happened they would look back and realize the significance of that earlier event. It is a powerful picture of God's sovereignty and love.
So as we approach this allegory, Paul's main point is that Isaac and Ishmael are a picture of those under grace and those under the Law.
Paul points out their desire to be under the law and warns them that they first should listen to what the law says. Now here Paul is using the term Law to refer to the whole Pentateuch, or first 5 books of the Bible. They were often collectively referred to as the law even though Genesis doesn't record the law. It is the genesis or beginnings of God's calling a people to himself in order to receive the law. So why would they desire to be under the law? Perhaps fear is a motivating factor, fear that they are not pleasing God unless they perform the law too. Also, the law gives a certainty of expectation. I am supposed to do this. Its commands are by in large external. And it gives a sense of accomplishment to those who are better at it than others, by comparison. Obviously these are not good reasons, but then their desire to be under the law is itself not good.
Paul points out different elements of Ishmael's story in the natural so that he might show the spiritual significance. God had promised Abraham and Sarah a miracle child. A miracle child because in the natural it was simply impossible for them to have children. They were too old. Tired of waiting and in order to do what God promised, Sarah hatches the scheme to give her servant Hagar to Abraham as a proxy, in order to have a child on her behalf. Thus Abraham would have a son. Paul's first point is that Ishmael was born by the will and intention of man. Also, he was born of a woman who was by nature a slave. Now it is here that Paul begins to turn to the allegory. Hagar is a picture of what happened at Sinai and what Jerusalem then represented in his day. At Sinai a nation was "born" to God who would be his "first-born." However, just as Ishmael was born to a slave woman, so Israel was born under a covenant that was by nature slavery. Though God loved them and they had a place in his house, they were still slave children. They represent the works and will of man to do in the flesh that which would please God. Jerusalem with its temple represented the "fruit" and current representative of that which was birthed at Sinai.
Notice in verse 25 that Paul says the "Jerusalem that now is." Paul hints at a distinction between the Jerusalem of his day and some other Jerusalem. It would be easy to think that he is looking ahead to the restoration of Israel in the last days, precisely what we are seeing today. But when you look at Paul's argument you see that he is going from the natural literal story to a symbolic spiritual meaning. Thus as Hagar is contrasted with Sarah, so Sinai is to be contrasted to Calvary or Golgatha. Also the natural Jerusalem is to be contrasted with what John saw in the book of Revelation, the New Jerusalem that will come down out of heaven. This is the city that is not built by men on this earth. All the cities and nations of this world are rejected by God, even America. He will bring a miracle city down to earth just as he birthed miracle children at the cross. But I get ahead of myself.
Paul quotes a passage from Isaiah that brings up another metaphor that is common in the Bible and that is the metaphor of the barren wife and the fruitful wife. Of course this is a natural connection because Sarah was such a stigmatized wife, she was barren. However, Hagar easily conceived. God had revealed an amazing and powerful truth to Isaiah. That which is fruitful in the natural is in the end barren in the spirit. But that which is barren in the natural has potential to be fruitful spiritually. We see this with the story of Hannah and her miracle child Samuel. Also in the struggle between Jacob's wives, Rachel and Leah. Rachel literally killed herself trying to give Jacob children in the natural and still failed to compare to Leah in the flesh. However Jacob's heart was still towards her and in the end, her son was the salvation of Israel in Egypt who kept Israel from being destroyed. In fact, all the nation of Israel from then on considered the fruit of Joseph's faith in God and his heart for God. The reason Paul brings this up is because the Law is fruitful in the natural. It's punishment and reward system is effective in increasing the amount of "righteous" acts. Israel looked down on the other nations who did not have the law and their societies were filled with all manner of evil things. The Gentiles were of the barren birth of God's grace. God had "overlooked" the rampant sin of the nations. Yes he intervened from time to time, but generally as they interacted with Israel. At the Cross the barren wife named Faith was made to be fruitful in the spirit. But the "fruitful" wife of the Law was revealed to be spiritually barren.
This is what Isaiah celebrates. He rejoices with the broken hearted barren wife who suddenly finds she has a child and names him laughter, Isaac, a miracle child!
Paul now turns to Isaac to press home the point with the Galatians. Isaac was not born at or by man's determination. He was born by the will of God at God's point in time. He is a picture of what John speaks of in John 1:12-13. Christians are saved through their faith in Jesus but that "work" of being saved is done completely by God. We would have nothing to believe in if God had not sent Jesus, the ultimate miracle child. Our belief in Jesus would do us no good if he had not taken our place on the cross and suffered in our stead. And our belief in Jesus would have no hope of a future if it were not for his resurrection and current intercession on our behalf. The Church was raised up not by the will of men who created a new cult. It was raised up by God in a miraculous way, like Isaac was.
Isaac is born to the free woman and so is by nature free himself. Thus those who come to God by His grace have no connection to the law and its slavery.
Here is Paul's final point. His point is not that no one was ever really saved in the time of the Law. Ishmael was in Abraham's house along for 13 years before Isaac was born. Then they both dwelled in the house together for a short time. But at some point Ishmael began to persecute and be hostile towards Isaac.
Most likely this was planted in him by his mother Hagar. There was friction between her and Sarah. Even though she was technically still a slave, she was proud of her ability to give Abraham a child and despised Sarah. She forgot her place and thought more highly of herself than she should have. This apparently infected her child and he began to persecute Isaac. This picture was to show the Galatians that those under the law would persecute those under Grace. In fact we still see that today even in the church. There has been an incredible tendency of the "Church" throughout history to be drawn back to keeping the law instead of walking by faith through Grace, following our Lord.
Let me challenge you with this today. The problem occurs when those who believe in Jesus continue on to do sinful things. The tendency is to retreat into the law and basically tell people that they can't be saved if they don't do certain things from the law. If gives a certain sense of comfort when we can point to things we do by our own will and power. However, we are in danger of losing sight of the grace of God, which Paul will demonstrate in the next chapter. No matter how "good" a life you live in Christ it will never merit salvation. Be careful that the subtle pride that rises in your heart because of good performance doesn't lead to you being cast out of the house. To those who have had trouble performing. Be careful that you don't let the persecution of those who point out your faults and put you down harden your heart to God. He cares about you and if you truly put your faith in him he will not only save you from your sins, but will teach you through life to let go of them.
How do we follow Christ? Dieing to our flesh. "Pick up your cross and follow me!"