We have seen that in 4:8-20 Paul spoke in an affectionate manner and appealed to the personal feeling of the Galatians. He did this for the purpose of ministering Christ to them. But in verse 21 Paul goes back to the tone he used in chapter three. In fact, he speaks to them in an even stronger way. In verses 22 and 23 Paul continues, “For it is written that Abraham had two sons, one of the maidservant and one of the free woman. But the one of the maidservant was born according to flesh, and the one of the free woman through the promise.” To be born according to flesh is to be born by man’s fleshly effort, whereas to be born through the promise is to be born through God’s power in grace, which is implied in His promise. Ishmael was born in the former way, but Isaac in the latter. According to the context, the law goes with the flesh, and grace goes with the promise. The child born of the maidservant was born according to the flesh, whereas the one born of the free woman was born according to grace. Because grace goes with the promise, to be born through promise is to be born through grace.
Speaking of the two women in verse 22, Paul says in verse 24, “Which things are an allegory; for these are two covenants, one from Mount Sinai, bringing forth children unto slavery, which is Hagar. Now this Hagar is Mount Sinai in Arabia, and corresponds to the Jerusalem which now is, for she is in slavery with her children.” Of the two covenants mentioned in verse 24, one is the covenant of promise to Abraham, which is related to the New Testament, the covenant of grace, and the other is the covenant of law related to Moses, which has nothing to do with the New Testament. Sarah, the free woman, represents the covenant of promise, and Hagar, the maidservant, the covenant of law.
Mount Sinai was the place where the law was given (Exo. 19:20). The slavery spoken of in verse 24 is the slavery under the law. Hagar, the concubine of Abraham, signifies the law. Hence, the position of the law is like that of a concubine. Sarah, the wife of Abraham, symbolizes the grace of God (John 1:17), which has the right position in God’s economy. The law, like Hagar, brought forth children unto slavery like the Judaizers. Grace, like Sarah, brings forth children unto sonship. These are the New Testament believers. They are no longer under law, but under grace (Rom. 6:14). They should stand in this grace (Rom. 5:2) and not fall from it (Gal. 5:4).
In verse 25 Paul mentions “the Jerusalem which now is.” Jerusalem, as the choice of God (1 Kings 14:21; Psa. 48:2, 8), should belong to the covenant of promise represented by Sarah. However, because it brings God’s chosen people into the bondage of law, it corresponds to Mount Sinai, which belongs to the covenant of law represented by Hagar. Jerusalem and her children were slaves under the law at Paul’s time.
Paul’s word in verses 24 and 25 was clear and strong. No doubt, the Judaizers must have been offended by it.
Verse 26 says, “But the Jerusalem above is free, who is our mother.” The mother of the Judaizers is the earthly Jerusalem, but the mother of believers is the heavenly Jerusalem. This will eventually be the New Jerusalem in the new heaven and new earth (Rev. 21:1-2), which is related to the covenant of promise. She is the mother of the New Testament believers, who are not slaves under law, but sons under grace. We, the New Testament believers, are all born of her from above.
Verse 27 goes on to say, “For it is written, Rejoice, barren one who does not bear; break forth and shout, you who are not travailing, because many are the children of the desolate rather than of her who has a husband.” This indicates that Abraham’s spiritual descendants, who belong to the heavenly Jerusalem, to the covenant of promise under the freedom of grace, are many more than his natural descendants, who belong to the earthly Jerusalem, to the covenant of law under the slavery of law.
According to Genesis 22:17, God promised that Abraham’s descendants would be like the sand of the seashore and like the stars of heaven. Here we see two kinds of descendants, the heavenly and the earthly, the spiritual and the natural. The Jews are Abraham’s descendants according to the flesh, whereas the believers in Christ are his descendants according to the Spirit. The natural descendants, the Jews, are like the sand of the seashore, but the spiritual descendants, the Christians, who outnumber the natural descendants, are like the stars.
Verse 28 continues, “But you, brothers, according to Isaac, are children of promise.” The children of promise are those born of the heavenly Jerusalem through grace under the covenant of promise.