justification by faith. So he wrote what we know as the Epistle to the Galatians, a stern letter of reproof and a wonderful exposition of how Christianity does not contradict but rather actually fulfills Old Testament Judaism. After establishing his apostolic credentials, Paul made his case for justification by faith alone using a revered Old Testament person (Abraham) and assorted Old Testament passages. Paul anticipated and refuted a possible objection to his use of Abraham to prove the doctrine