Galatians 2:11-13 Now when Peter had come to Antioch, I withstood him to his face, because he was to be blamed; for before certain men came from James, he would eat with the Gentiles; but when they came, he withdrew and separated himself, fearing those who were of the circumcision. And the rest of the Jews also played the hypocrite with him, so that even Barnabas was carried away with their hypocrisy.
Peter had been told by God that he should not call unclean what He, God calls clean (Acts 10). He had then been sent by the Holy Spirit to the house of Cornelius, where he witnessed to Gentiles, and saw God pour His Spirit upon them. Therefore Peter was certain in his heart that God wanted to save Jews and Gentiles alike.
But there came a time, when Peter was moved by the fear of men, his fellow Jews precisely. These people had an air of righteousness around them, with a belief that they as Jews were the authentic children of God, and did not need to mingle with the Gentiles - Peter wanted to be in the good books of his fellow Jews, so though he had been mingling with the saved Gentiles, he isolated himself from them when he thought it will displease his Jewish friends.
God had warned - do not call what I call clean, unclean. Peter knew this but was acting as though the Gentile Christians were unclean. He had started to listen to the voice of man rather than the voice of God. He otherwise wanted to please man than God. We must learn to stand alone to please God. We must desire to obey God even if we need to disobey men in the process.
Obedience to God is better than sacrifice!
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