In the Acts of the Apostles, a voice was heard by Peter, saying unto him, “Rise, Peter, slay and eat,” when all manner of four-footed beasts, and creeping things, and birds of the air, were presented before him; by which saying it is proved that no man is by nature [ceremonially] unclean, but that all men are equally welcome to the gospel of Christ. To which Peter answered, “Not so, Lord; for I have never eaten anything that is common or unclean.” And the voice spoke unto him again the second time, “What God has cleansed, call not common.” Therefore he went to Cæsarea, and having entered the house of Cornelius, “he opened his mouth and said, Of a truth I perceive that God is no respecter of persons, but in every nation he that fears Him and works righteousness is accepted with Him.” Thereafter “the Holy Ghost fell on all them which heard the word; and they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost. Then answered Peter, Can any man forbid water, that these should not be baptized, which have received the Holy Ghost as well as we? And he commanded them to be baptized in the name of the Lord.” “And the apostles and brethren that were in Judea heard that the Gentiles had also received the word of God. And when Peter had come up to Jerusalem, they that were of the circumcision contended with him, saying, You went in to men uncircumcised, and ate with them.” To whom he gave a full explanation of the reasons of his conduct, and concluded with these words: “Forasmuch then as God gave them the like gift as He did unto us who believed on the Lord Jesus Christ, what was I, that I could withstand God? When they heard these things, they held their peace, and glorified God, saying, Then has God also to the Gentiles granted repentance unto life.” Again, when, long after this, Paul and Barnabas had come to Antioch, and “having gathered the Church together, rehearsed all that God had done with them, and how He had opened the door of faith unto the Gentiles, certain men which came down from Judea taught the brethren, and said, Unless you are circumcised after the manner of Moses, you cannot be saved. When therefore Paul and Barnabas had no small dissension and disputation with them, they determined that Paul and Barnabas, and certain other of them, should go up to Jerusalem unto the apostles and elders about this question. And when they had come to Jerusalem, there rose up certain of the sect of the Pharisees which believed, saying that it was needful to circumcise them, and to command them to keep the law of Moses.” And when there had been much disputing, Peter rose up, with his wonted readiness, “and said, Men and brethren, you know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe. And God, which knows the hearts, bare them witness, giving them the Holy Ghost, even as He did unto us; and put no difference between us and them, purifying their hearts by faith. Now therefore why do you tempt God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear? But we believe that, through the grace of the Lord Jesus Christ, we shall be saved, even as they. Then all the multitude kept silence;” and to his opinion the Apostle James, and all the elders together, gave consent.
8. These quotations should not be tedious to the reader, but useful both to him and to me, as proving that, even before the Apostle Paul, Peter had come to know that the law was not to be in force after the gospel was given; nay more, that Peter was the prime mover in issuing the decree by which this was affirmed. Moreover, Peter was of so great authority, that Paul has recorded in his epistle: “Then, after three years, I went up to Jerusalem to see Peter, and abode with him fifteen days.” In the following context, again, he adds: “Then, fourteen years after, I went up again to Jerusalem with Barnabas, and took Titus with me also. And I went up by revelation, and communicated unto them that gospel which I preach among the Gentiles;” proving that he had not had confidence in his preaching of the gospel if he had not been confirmed by the consent of Peter and those who were with him. The next words are, “but privately to them that were of reputation, lest by any means I should run, or had run, in vain.” Why did he this privately rather than in public? Lest offense should be given to the faith of those who from among the Jews had believed, since they thought that the law was still in force, and that they ought to join observance of the law with faith in the Lord as their Saviour. Therefore also, when at that time Peter had come to Antioch (although the Acts of the Apostles do not mention this, but we must believe Paul's statement), Paul affirms that he “withstood him to the face, because he was to be blamed. For, before that certain came from James, he did eat with the Gentiles: but when they had come, he withdrew, and separated himself, fearing them which were of the circumcision. And the other Jews dissembled likewise with him; insomuch that Barnabas also was carried away with their dissimulation. But when I saw,” he says, “that they walked not up-rightly, according to the truth of the gospel, I said unto Peter before them all, If you, being a Jew, livest after the manner of Gentiles, and not as do the Jews, why do you compel the Gentiles to live as do the Jews?” etc. No one can doubt, therefore, that the Apostle Peter was himself the author of that rule with deviation from which he is charged. The cause of that deviation, moreover, is seen to be fear of the Jews. For the Scripture says, that “at first he did eat with the Gentiles, but that when certain had come from James he withdrew, and separated himself, fearing them which were of the circumcision.” Now he feared the Jews, to whom he had been appointed apostle, lest by occasion of the Gentiles they should go back from the faith in Christ; imitating the Good Shepherd in his concern lest he should lose the flock committed to him.
9. As I have shown, therefore, that Peter was thoroughly aware of the abrogation of the law of Moses, but was compelled by fear to pretend to observe it, let us now see whether Paul, who accuses another, ever did anything of the same kind himself. We read in the same book: “Paul passed through Syria and Cilicia, confirming the churches. Then came he to Derbe and Lystra: and, behold, a certain disciple was there, named Timotheus, the son of a certain woman which was a Jewess, and believed; but his father was a Greek: which was well reported of by the brethren that were at Lystra and Iconium. Him would Paul have to go forth with him; and he took and circumcised him, because of the Jews which were in those quarters: for they knew all that his father was a Greek.” O blessed Apostle Paul, who had rebuked Peter for dissimulation, because he withdrew himself from the Gentiles through fear of the Jews who came from James, why are you, notwithstanding your own doctrine, compelled to circumcise Timothy, the son of a Gentile, nay more, a Gentile himself (for he was not a Jew, having not been circumcised)? You will answer, “Because of the Jews which are in these quarters?” If, then, you forgive yourself the circumcision of a disciple coming from the Gentiles, forgive Peter also, who has precedence above you, his doing some things of the same kind through fear of the believing Jews. Again, it is written: “Paul after this tarried there yet a good while, and then took his leave of the brethren, and sailed thence into Syria, and with him Priscilla and Aquila; having shorn his head in Cenchrea, for he had a vow.” Be it granted that he was compelled through fear of the Jews in the other case to do what he was unwilling to do; wherefore did he let his hair grow in accordance with a vow of his own making, and afterwards, when in Cenchrea, shave his head according to the law, as the Nazarites, who had given themselves by vow to God, were wont to do, according to the law of Moses?
Source: Letters (New Advent)