Galatians 6:13

"As many as desire to make a fair show in the flesh, they compel you to be circumcised; only that they may not be persecuted for the cross of Christ. For not even they who receive circumcision do themselves keep the Law; but they desire to have you circumcised, that they may glory in your flesh." Here he shows that they suffered this, not willingly but of necessity, and affords them an opportunity of retreat, almost speaking in their defence, and exhorting them to abandon their teachers with all speed. What is the meaning of "to make a fair show in the flesh?" it means, to be esteemed by men. As they were reviled by the Jews for deserting the customs of their fathers, they desire, says he, to injure you, that they may not have this charged against them, but vindicate themselves by means of your flesh. His object here is to show that they did not so act from respect to God; it is as if he said, This procedure is not founded in piety, all this is done through human ambition; in order that the unbelievers may be gratified by the mutilation of the faithful, they choose to offend God that they may please men; for this is the meaning of, "to make a fair show in the flesh." Then, as a proof that for another reason too they are unpardonable, he again convinces them that, not only in order to please others, but for their own vain glory, they had enjoined this. Wherefore he adds, "that they may glory in your flesh," as if they had disciples, and were teachers. And what is the proof of this? "For not even they themselves," he says, "keep the Law;" even if they did keep it, they would incur grave censure, but now their very purpose is corrupt.