In the Jews' religion;— This does not signify the religion originally taught by Moses, but that which was practised among the Jews at this time, and much of it built upon the tradition of the elders. Grotius.
Related Commentaries of Galatians 1:13
Galatians 1:13
13 For ye have heard of my conversation in time past in the Jews' religion, how that beyond measure I persecuted the church of God, and wasted it: