In the relationship between the two sons of Abraham, Paul finds an allegorical reference to the relationship between the Jews, particularly the false teachers, and the Christians, particularly the Galatian believers.

The son who was born in the usual way (literally, “the one born according to the flesh,” as in verse 23) refers to Ishmael, and the one who was born because of God’s Spirit refers to Isaac. For God’s Spirit, the Greek simply has “spirit,” and while some translations take this in the sense of “spiritual” (New English Bible, Phillips, Knox, New American Bible), it is in accordance with Pauline usage to take this as referring to the Holy Spirit (Good News Translation, Jerusalem Bible). The switch from “promise” (verses 23,28) to “spirit” reminds us of the language of chapter 3.

As in the case of verse 23, it is important to render the son who was born in the usual way in a manner which will not suggest some physical aspect of birth. In this context it may be necessary in some languages simply to say “At that time Abraham’s son by means of Hagar persecuted the son who was born because of what God’s Spirit had said,” or “… because of what God’s Spirit had done.” The Greek text simply says “according to spirit,” but since the focus has been upon the birth of Isaac resulting from the promise of God, it is quite legitimate to fill out the semantic ellipsis by indicating that the birth took place as “the result of what God’s Spirit had promised,” or “… caused to happen.”

The final clause and it is the same now refers either to the persecution or to the type of personalities involved. One may therefore say “and the same kind of persecution takes place now,” or “there are the corresponding kinds of persons even now.”

Quoted with permission from Arichea, Daniel C. and Nida, Eugene A. A Handbook on Paul’s Letter to the Galatians. (UBS Handbook Series). New York: UBS, 1976. For this and other handbooks for translators see here .