Galatians 2:11-14 Paul reproves Peters character

Notwithstanding Peter's character, yet, when Paul saw him acting so as to hurt the truth of the gospel and the peace of the church, he was not afraid to reprove him. When he saw that Peter and the others did not live up to that principle which the gospel taught, and which they professed, namely, That by the death of Christ the partition wall between Jew and Gentile was taken down, and the observance of the law of Moses was no longer in force; as Peter's offence was public, he publicly reproved him. There is a very great difference between the prudence of St. Paul, who bore with, and used for a time, the ceremonies of the law as not sinful, and the timid conduct of St. Peter, who, by withdrawing from the Gentiles, led others to think that these ceremonies were necessary. 

From the account which Paul gives of what passed between him and the other apostles at Jerusalem, the Galatians might easily discern both the falseness of what his enemies had insinuated against him and their own folly and weakness in departing from that gospel which he had preached to them. But to give the greater weight to what he had already said, and more fully to fortify them against the insinuations of the judaizing teachers, he acquaints them with another interview which he had with the apostle Peter at Antioch, and what passed between them there,  Gal_2:11-14.

Antioch was one of the chief churches of the Gentile Christians, as Jerusalem was of those Christians who turned from Judaism to the faith of Christ. There is no colour of reason for the supposition that Peter was bishop of Antioch. If he had, surely Paul would not have withstood him in his own church, as we here find he did; but, on the contrary, it is here spoken of as an occasional visit which he made thither. In their other meeting, there had been good harmony and agreement. Peter and the other apostles had both acknowledged Paul's commission and approved his doctrine, and they parted very good friends. But in this Paul finds himself obliged to appose Peter, for he was to be blamed,a plain evidence that he was not inferior to him, and consequently of the weakness of the pope's pretence to supremacy and infallibility, as the successor of Peter. Here we may observe,

Peter's fault. When he came among the Gentile churches, he complied with them, and did eat with them, though they were not circumcised, agreeably to the instructions which were given in particular to him (Acts 10), when he was warned by the heavenly vision to call nothing common or unclean. But, when there came some Jewish Christians from Jerusalem, he grew more shy of the Gentiles, only to humour those of the circumcision and for fear of giving them offence, which doubtless was to the great grief and discouragement of the Gentile churches. Then he withdrew, and separated himself. His fault herein had a bad influence upon others, for the other Jews also dissembled with him; though before they might be better disposed, yet now, from his example, they took on them to scruple eating with the Gentiles, and pretended they could not in conscience do it, because they were not circumcised. And (would you think it?) Barnabas himself, one of the apostles of the Gentiles, and one who had been instrumental in planting and watering the churches of the Gentiles, was carried away with their dissimulation.Here note, (1.) The weakness and inconstancy of the best of men, when left to themselves, and how apt they are to falter in their duty to God, out of an undue regard to the pleasing of men. And, (2.) The great force of bad examples, especially the examples of great men and good men, such as are in reputation for wisdom and honour.

The rebuke which Paul gave him for his fault. Notwithstanding Peter's character, yet, when he observes him thus behaving himself to the great prejudice both of the truth of the gospel and the peace of the church, he is not afraid to reprove him for it. Paul adhered resolutely to his principles, when others faltered in theirs; he was as good a Jew as any of them (for he was a Hebrew of the Hebrews), but he would magnify his office as the apostle of the Gentiles, and therefore would not see them discouraged and trampled upon. When he saw that they walked not uprightly, according to the truth of the gospel - that they did not live up to that principle which the gospel taught, and which they had professed to own and embrace, namely, that by the death of Christ the partition-wall between Jew and Gentile was taken down, and the observance of the law of Moses was no longer in force - when he observed this, as Peter's offence was public, so he publicly reproved him for it: He said unto him before them all, If thou, being a Jew, livest after the manner of the Gentiles, and not as do the Jews, why compellest thou the Gentiles to live as do the Jews? Herein one part of his conduct was a contradiction to the other; for if he, who was a Jew, could himself sometimes dispense with the use of the ceremonial law, and live after the manner of the Gentiles, this showed that he did not look upon the observance of it as still necessary, even for the Jews themselves; and therefore that he could not, consistently with his own practice, impose it upon the Gentile Christians. And yet Paul charges him with this, yea, represents him as compelling the Gentiles to live as did the Jews - not by open force and violence, but this was the tendency of what he did; for it was in effect to signify this, that the Gentiles must comply with the Jews, or else not be admitted into Christian communion.