Adam Clarke on Galatians 3:25

But, after that faith is come - When Christ was manifested in the flesh, and the Gospel was preached, we were no longer under the pedagogue; we came to Christ, learned of him, became wise unto salvation, had our fruit unto holiness, and the end eternal life.

It is worthy of remark that, as ὁ νομος, the Law, is used by St. Paul to signify, not only the law, properly so called, but the whole of the Mosaic economy, so ἡ πιστις, the Faith, is used by him to express, not merely the act of believing in Christ, but the whole of the Gospel.