What did Paul mean when he said that we aren’t justified by works of the law (Gal. 2:16)?
Paul wrote, “We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified” (Gal. 2:15-16).
Contextually, he was addressing the problem commonly found among the Galatian churches of “Judaizers,” i.e., brethren who were promoting that one must obey certain tenets of the law of Moses in order to be saved. The theme of the book of Galatians is basically a divinely-inspired refutation of that erroneous doctrine.
Thus, “the law” refers to the law of Moses, the Old Testament. Under Christianity, the new covenant, one is not justified through obedience to the commands of the law of Moses (“works of the law”). Rather, one is justified “through faith in Jesus Christ.” James would additionally teach that a living faith in the sight of God requires works of obedience (James 2:14-26). Since we are under the New Testament and not under the Old, this would be obedience to the commandments found in the New Testament, not the Old.