Tell me, you who desire to be under law, do you not hear the law? For it is written that Abraham had two sons, one by a slave and one by a free woman. But the son of the slave was born according to the flesh, the son of the free woman through promise. Now this is an allegory: 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 shout, you who are not in travail;
for the children of the desolate one are many more
than the children of her that is married."

Now we, 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. But what does the scripture say? "Cast out the slave and her son; for the son of the slave shall not inherit with the son of the free woman." So, brethren, we are not children of the slave but of the free woman.

The allegory of Hagar and Sarah is written to persuade us (along with the Galatians) not to follow the Judaizers into slavery with Hagar and Ishmael, but to follow Sarah and Isaac into freedom. So I want to begin with a definition of freedom that I think is implied here. Then we will look at the allegory and learn from it how to have freedom.

Full Freedom

Full freedom is what you have when no lack of opportunity, no lack of ability, and no lack of desire prevents you from doing what will make you happiest in a thousand years. In order to be free in the fullest sense you have to have opportunity, ability, and desire to do what will make you happy in a thousand years. Another way to say it would be that there are four kinds of freedom, or better, four stages of freedom on the way to the full freedom all of us long for: the freedom of opportunity to do what we can, the freedom of ability to do what we desire, and the freedom of desire to do what will bring us unending joy.

Let's take sky-jumping, for example. Suppose you are on your way to the airport to go up for your first real jump, but your car hits a pothole on Hiawatha, you have a blowout, and run into a telephone pole. You are no longer free to jump whether you have the ability or not, because the opportunity passes while you wait for the tow truck. You lack the freedom of opportunity.

Or suppose you do make it to the airport, but you have no ability at all—you have never studied sky-jumping and never learned the first thing about how a parachute works. The opportunity is there, but you don't have the freedom of ability—you are in bondage to your own lack of know-how.

But suppose that you make it to the airport, you've been to school and been trained and have all the abilities needed, and you take off for your first jump. But as soon as you look down, all your desire vanishes and in its place comes a tremendous fear. The opportunity is there, the ability and know-how are there, but you don't have the freedom of desire. The interesting thing about the freedom of desire is that you might be able to go ahead and jump without it, but it won't be a free act. For example, you might feel so humiliated in front of your instructor (or girlfriend) that the desire not to be humiliated overcomes the desire not to jump. So you jump. But the emotional experience is not what we call freedom. You are acting under very uncomfortable external constraints. You are like Herod when his step-daughter asked for the head of John the Baptist. He didn't want to kill John, but he wanted even less to be shamed before his guests. So he acted, but not with the freedom of desire. You have the freedom of desire when you do what you love to do.

That's the way a lot of professing Christians try to keep the commandments of Christ. They don't really delight to do them, but they feel some uncomfortable constraints like social pressures or fear of hell or desire to impress someone. So they go through outward motions of obedience, but the desire of their hearts is fixed somewhere else. They do not enjoy the freedom of desire which Christ gives when he is being formed in the heart (Galatians 4:19).

But there is one last requirement for full freedom. Suppose you get to the airport with no obstacle; you have all the know-how necessary; you look out the door at the tiny clusters of silos and barns and farmhouses and just can't wait to jump. You have freedom of opportunity, freedom of ability, and freedom of desire. So you jump. And as you free fall, unbeknown to you, your parachute malfunctions and will not open. Are you free? In three senses, yes. But in that critical fourth sense, no. What you are doing so happily, so freely, is going to kill you. Whether you know it or not, you are in bondage to destruction. It would be a mockery to exult in the freedom of an exhilarating free fall if you knew it was leading to destruction. In order to be fully free, it is not enough to have opportunity, ability, and desire to act. The acts you desire and perform have to lead to life, indeed, eternal life not destruction.

This is why it is naïve for a Christian young person to envy the so-called freedom of those who pitch themselves out the window of sin and exult for a season in the exhilaration of free fall sex or free fall greed, or free fall drugs or free fall luxury. They will pass away like a vapor, but those who do the will of the Lord will abide for ever (1 John 2:17). True freedom is not just the opportunity and ability to do what you desire to do. It is the opportunity, ability, and desire to do what will make you happy in a thousand years.

Therefore, true Christians are the freest people in the world. And Paul is fighting with all his might in Galatians to expose the teaching of the Judaizers for what it really is: slavery. For Paul, the experience of freedom is not icing on the cake of Christianity. Freedom in Christ is Christianity. It is a matter of eternity. That's the first point of the allegory. So let's see if we can understand it and strengthen our stand in freedom.

What the Law Teaches About Freedom

In verse 21 Paul simply says that those who are turning back to the law of Moses as a job description for how to earn the wages of blessing from God should listen to what the law says. Note this well, lest anything I or Paul have said sounds anti-Semitic. Paul only wants to teach things that are implied in the Jewish Bible. His problem with the Judaizers is not that they are Jewish, but that they aren't Jewish enough. Paul himself was a Jew and never surrendered his allegiance to the law. What does it teach about freedom?

Verses 22 and 23, "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, the son of the free woman through promise." Let's go back to Genesis 15 and remind ourselves of what happened to Abraham and Sarah. In Genesis 15:1–6 Abraham is downcast because he and Sarah have no children, no heir to fulfill the promises of becoming a great nation (12:2). There is only Eliezer the slave. But God says in verse 4, "This man shall not be your heir; your own son shall be your heir." God's intention was to give Abraham a son and an heir when it looked humanly impossible so that Abraham would have to rely solely on God.

But in Genesis 16 Abraham and Sarah weaken in their faith for a time and devise a plan by which they will use their own resources to help God fulfill his promise. Sarah gives Hagar, her handmaid, to Abraham so she can bear him a son (16:2). And in Genesis 16:15 it says, "Hagar bore Abram a son, and Abram called the name of his son whom Hagar bore to him Ishmael." So when Paul says in Galatians 4:23 that Ishmael was born "according to the flesh," it means that he was the product of self-reliance. Abraham ceased to rely on God's power to fulfill his word and instead relied on his own power and ingenuity to get a son.

Then, 14 years later, in Genesis 17:16 God says to Abraham that his wife, Sarah, will have a son. God intends to fulfill his promise in a way that removes all ground for boasting. In verses 17–19 it says, "Abraham fell on his face and laughed and said to himself, 'Shall a child be born to a man who is a hundred years old? Shall Sarah who is ninety years old bear a child?' And Abraham said to God, 'O, that Ishmael might live in thy sight!' God said, 'No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his descendants after him.'" God rejects what Abraham was able to produce on his own and promises again that in spite of Abraham's age, he will have a son by his own wife. So in Genesis 21:1 it says, "The Lord visited Sarah as he had said, and the Lord did to Sarah as he had promised." Isaac was not born according to the flesh because his birth was the result of God's supernatural intervention in fulfillment of his own promise. Abraham had learned his lesson: the only acceptable response to God's merciful promise is trust in that promise, not works of the flesh that try to bring down God's blessing with our efforts. So Galatians 4:23 sums up the story: "The son of the slave was born according to the flesh, the son of the free woman through promise."

The Allegory of Hagar and Sarah

Verse 24 says that Paul sees an allegory in these events, that is, he sees them as apt representations of something more than their literal meaning. I don't think Paul would say that the original meaning of Genesis had reference to Mt. Sinai or to Jerusalem. I think he would say that the truth implied in the stories about Hagar and Sarah is the same truth that we can now see in what happened at Mt. Sinai and continues to happen in the present Jerusalem. So it is fully legitimate to use those stories from Genesis to symbolize and illustrate the later events.

According to verse 24, Hagar and Sarah represent two covenants. First, he focuses on Hagar and says, "One (covenant) is from Mt. Sinai, bearing children for slavery; she is Hagar. Now Hagar is Mt. Sinai in Arabia; she corresponds to the present Jerusalem, for she is in slavery with her children." The key question here is: how is Hagar and her affair with Abraham and their son Ishmael like the covenant of Mt. Sinai—the giving of the law through Moses?

There are two similarities, at least. Hagar's giving birth to Ishmael is done "according to the flesh" (v. 23); Abraham and Hagar tried to get God's promised blessing by their own strength without relying on God's supernatural enablement. That is just what happened when the law was given at Mt. Sinai. Instead of humbling themselves and trusting God for help to obey his commands, Israel says confidently, "All the words which the Lord has spoken we will do" (Exodus 24:3; Deuteronomy 5:27). But they did not have hearts inclined to trust in God (Hebrews 4:2) or truly depend on him (Deuteronomy 5:29). And so like Hagar and Abraham they depended on their own resources. And just as Ishmael was born according to the flesh, so the law offered was not received because (as Romans 8:3 says) the law was "weakened by the flesh." All that Abraham and Hagar produced on their own was a son who would not be the heir. All that Israel produced when they tried to keep the law on their own was a legalism which would inherit nothing.

Which leads to the second similarity between Hagar and Mt. Sinai—both of them bear children for slavery. Verse 24 says that the covenant Hagar represents is from Mt. Sinai "bearing children for slavery." Since Ishmael was not accepted as an heir, he was no better than his mother, a slave. And when the Israelites take the law upon themselves without trusting God for gracious enablement, they become slaves because they have no freedom to do the law from the heart, and because their unbelief locks them into disobedience and excludes them from the inheritance.

Then to bring the allegory up to date, at the end of verse 25 Paul says, "She corresponds to the present Jerusalem, for she is in slavery with her children." This is a direct attack on the Judaizers who have come from Jerusalem (cf. 2:12). They are the children of Jerusalem, and they are slaves to the law and to the demonic forces of the world (4:3, 8). So you can see Paul's point: don't follow these false teachers—they may show you how to become sons of Abraham, but beware! With them you will be an Ishmael, not an Isaac. A slave, not an heir.

Then in verse 26 Paul turns his attention to the other half of the allegory—Sarah and her child, Isaac. But he skips over any mention of the (Abrahamic) covenant and gets right up to date: "But the Jerusalem above is free, and she is our mother." He contrasts the present Jerusalem in verse 25 with the "Jerusalem above" in verse 26. What he means by the Jerusalem above can be seen in Colossians 3:1–3, "If then you have been raised with Christ, seek the things that are above, where Christ is seated at the right hand of God. Set your minds on things that are above, not on things that are on the earth. For you have died and your life is hid with Christ in God." The Jerusalem above represents the dwelling place of God. Our life and our freedom flow down from him, and our lives are already secure on the citizen books of that city. Sarah represents that city because she gave birth to Isaac not by reliance on herself but by an act of God from above in fulfillment of his promise.

Therefore, spiritually speaking, she is the mother of all Christians—of people whose lives are not merely the product of human resources but of God's supernatural work in their heart. So Paul says in verse 28, "Now we, brethren, like Isaac, are children of promise." Our real life is not, like Ishmael's, simply owing to the work of man. Our real life is owing to the work of God in us fulfilling his promise to make for himself a people (Genesis 12:1–3) and to put his Spirit within them (Ezekiel 36:27) and write his law on their hearts (Jeremiah 31:33).

This is confirmed by the contrast in verse 29. It says, "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." Recall how in verse 23 the contrast was between one born according to the flesh and one born through promise. But notice here in verse 29 that the same contrast is between one born according to the flesh and one born according to the Spirit. "Born according to the Spirit" is interchangeable with "born through promise." This confirms that "children of promise" in verse 28 refers to people whose inner life is the work of God's Spirit in fulfillment of his promise. The difference between Ishmael-types and Isaac-types is a supernatural work of the Spirit of God.

Then verse 30 assures us that not the Ishmael-types—not the Judaizers—but the Isaac-types will inherit the blessing of Abraham, even though they may be persecuted. Finally, Paul concludes in verse 31 that we—that is, we who live by faith in the Son of God and don't rely on what we can achieve on our own—are not in the slave category but in the category of the free.

The Freedom of the Children of Promise

Which brings us back to our definition of freedom. Freedom is what you have when there is opportunity, ability, and desire to do what will make you happy in a thousand years. Surely everyone here wants this full freedom—to have occasion and ability to do what you love to do with the result that you live in perfect joy forever. If that's what you want, then this text is crucial for you, because Paul says the Ishmael-types don't have this freedom but the Isaac-types do.

Why aren't the Ishmael-types free? They are not free because they lack the desire to rest in God's promises. They lack the desire to show their own resourcefulness. It's not that they desire to reject God. They simply want him on their own terms. Abraham and Hagar wanted God's blessing, but not on his terms.

The Judaizers want God's blessing, but not on his terms. Ishmael-types in every age rely on human resources and don't desire to feel like children in need of a father, or like a patient in need of a doctor. Ishmael-types think you can outgrow:

Jesus loves me, this I know
For the Bible tells me so.
Little ones to him belong,
We are weak but he is strong.

Therefore, when it comes to saving faith, Ishmael-types do not have the freedom of desire. They do not want it. Therefore, they also lack the freedom of eternal life, because no one who prefers to live in his own strength rather than trusting God will be saved and go to heaven. And what's more, the hardness of heart that spurns childlike dependence on God will also darken the understanding. Every one of us knows that the most common use of the mind is to justify our desires. Therefore, deeply wrong desires will deeply mislead the mind until it is not able to understand what is right. So Ishmael-types are not free because they lack the freedom of desire to rest in God's sovereign grace; and therefore, they lack the freedom of ability to understand God's will; and finally, they lack the freedom of eternal joy, because the life they have chosen leads to destruction.

But we, brothers and sisters, like Isaac, are children of promise (Galatians 4:28). We have been born of the Holy Spirit. The essence of Christianity is the miracle of new birth. The hallmark of the Isaac-types is that we have been converted, changed, transformed at the center of our lives, so that we desire to rest in God's sovereign grace. We desire to become as little children and receive the power and wisdom and holiness from our all-sufficient Father. We hate the remaining tendencies in us to be proud and to trust in ourselves or other people instead of God. Our delight is in the law of the Lord, and our choicest food is to do his will in reliance on his power. This is what it means to be born according to the Spirit. This is what it means to say I no longer live but Christ lives in me (Galatians 2:20). His passion becomes our passion.

Therefore, Isaac-types have the freedom of desire. We don't labor slavishly under the burden of having to do what we don't want to do. We are free to do what we love to do and to do it forever in perfect joy. For God has caused us to be born again by the Spirit of his Son, and is shaping our desires according to his will.

"For freedom Christ has set us free! Stand fast, therefore, and do not submit again to a yoke of slavery."