Galatians 4:21-31

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 in the ordinary way; but his son by the free woman was born as the result of a promise.

These things may be taken figuratively, for 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, O barren woman,

who bears no children;

break forth and cry aloud,

you who have no labor pains;

because more are the children of the desolate woman

than of her who has a husband."

Now you, brothers, like Isaac, are children of promise. At that time the son born in the ordinary way persecuted the son born by the power of the Spirit. It is the same now. But what does the 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, we are not children of the slave woman, but of the free woman.

(v21-31, NIV)

I'm not going to go into much detail today. Maybe I will another day, we'll see. Apparently, this is a difficult passage to understand according to something I read. Regardless, the Word of God is awesome and let's not get scared or anything.

By simply looking at the beginning and the end we can see what Paul is doing here. Paul begins by making a distinction between Abraham's two sons. If you didn't already know, Abraham and Sarai were getting older but not being able to have children. So eventually, Sarai allowed Abraham to try with her maid Hagar. Hagar then gave birth to Ishmael. It wasn't until later that Sarah (whose name had been changed by now from Sarai to Sarah) gave birth to Isaac.

Looking to the end, we see that Paul's point is that we are the children of promise. We are being compared to Issac instead of Ishmael and are inheritors of the promise. Since Isaac is a son of Sarah who is the free woman, so we too are children of the free woman.