12. For before that certain persons came. The state of the case is here laid down. For the sake of the Jews, Peter had withdrawn himself from the Gentiles, in order to drive them from the communion of the Church, unless they would relinquish the liberty of the Gospel, and submit to the yoke of the Law. If Paul had been silent here, his whole doctrine fell; all the edification obtained by his ministry was ruined. It was therefore necessary that he should rise manfully, and fight with courage. This shews us how cautiously we ought to guard against giving way to the opinions of men, lest an immoderate desire to please, or an undue dread of giving offense, should turn us aside from the right path. If this might happen to Peter, how much more easily may it happen to us, if we are not duly careful!