2:4 false brothers. Paul considered the doctrine of salvation by grace through faith alone to be so important that he excluded from the church all who did not hold to it (1:8, 9; 5:2–4).
freedom. The freedom of the believer is not freedom to sin, but freedom from the curse the law pronounces on sin (3:10–14; 5:1, 13).
slavery. Probably bondage to sin (Rom. 6:15–23; 7:25) and to the curse that the law pronounces on those who sin (3:10).