Tell me, you who want to be under the law, are you not aware of what the law says? For it is written that Abraham had two sons, one by the slave woman and the other by the free woman. His son by the slave woman was born according to the flesh, but his son by the free woman was born as the result of a divine promise.
These things are being taken figuratively: The women represent two covenants. One covenant is from Mount Sinai and bears children who are to be slaves: This is Hagar. Now Hagar stands for Mount Sinai in Arabia and corresponds to the present city of Jerusalem, because she is in slavery with her children. But the Jerusalem that is above is free, and she is our mother. For it is written:
“Be glad, barren woman,
you who never bore a child;
shout for joy and cry aloud,
you who were never in labor;
because more are the children of the desolate woman
than of her who has a husband.”
It’s funny, every time I read this I’m surprised, even though I know what’s coming. This was radical in Paul’s day, and for some reason it’s still radical in our day. It flies in the face of the teaching of many Christians concerning Israel, and yet there it is…
The really radical part begins with verse 24: “These things are taken figuratively” Then, “The women represent two covenants…” In his analysis, taken under the inspiration of the Holy Spirit, Paul is stating quite clearly that Hagar and Ishmael represent the Old Covenant (the Law of Moses) and that Sarah and Isaac represent the New Covenant. But wait, there’s more…!
Now you, brothers and sisters, like Isaac, are children of promise. At that time the son born according to the flesh persecuted the son born by the power of the Spirit. It is the same now. But what does Scripture say? “Get rid of the slave woman and her son, for the slave woman’s son will never share in the inheritance with the free woman’s son.” Therefore, brothers and sisters, we are not children of the slave woman, but of the free woman.
We are children of the promise as Isaac was the son of promise. This is the promise that God made to Abraham, the promise that his descendants would be more numerous that the stars in the heavens or the grains of sand on the shore, and that all of the nations of the earth would be blessed though them. Earlier in this letter, Paul indicated that Jesus was that descendant, the seed. Here, through Christ, Paul is telling us that we carry this forward as descendants of Abraham not according to the flesh, but according to the promise of God. Yes, just as Isaac was persecuted by Ishmael, so the church was persecuted by the Jews in Paul’s day, but as Hagar and Ishmael were driven out by Abraham, so now those who persecuted the church would be driven out, for they would not inherit the promise.
Honestly, I’m not sure how much clearer it could be, and there is still more to come in the next chapter…