That Paul employs the image of rebirth for conversion in Galatians 4:28-29 is no accident. Galatian gentiles might think of some gentile traditions of regeneration, but that is not the source of Paul’s image. Rebirth from God’s Spirit or word was a familiar early Christian image (John 1:12-13; 3:3-6; 1 Pet. 1:23; 1 John 3:9), but it also plays on an image of conversion probably already circulating in first-century Judaism. In the Diaspora, Justin Martyr also testifies independently to the mid-second-century Jewish belief, apparently widespread, that the proselyte is “like one who is native born.” It was, in fact, a commonplace that a proselyte’s status was that of a newborn child. A convert was no longer the person he or she had been as a gentile, before God, the law, or Israel; his or her legal standing was that of an Israelite.
In the halakah, a proselyte had lost all previous connections; the convert had begun a new life. This may bear some relation to a Roman custom in which one becoming a Roman citizen had to explicitly reaffirm prior legal ties for them to remain binding. Thus, in terms of legal status, a proselyte had no relatives and could marry paternal relatives; according to legal theory, though not practice, a proselyte could even marry his former mother. It may not be surprising that gentiles accused converts to Judaism of disowning their families of origin. Many early Palestinian Amoraim understood Tannaitic authorities to say that a proselyte had no inheritance obligation to his former children. A proselyte was still, however, allowed to inherit from gentile parents.
Conversion to Judaism was in a sense adoption into a new ethnic community. In Gal. 4, God adopts gentiles as his children without their adopting a new ethnicity-though as children of Abraham they should see themselves as grafted into the heritage and story of ancient Israel.
This content is by Craig Keener, but edited and posted by Defenders Media.
For more on the book of Galatians, please check out Galatians: A Commentary.