For before certain men came from James, he did eat with the Gentiles: but when they were come, he withdrew and separated himself, fearing them who were of the circumcision.
All Commentaries on Galatians 2:12 Go To Galatians 2
Gaius Marius Victorinus
AD 400
Perhaps indeed he would at this point have kept silent about the sin that he says he reproved in Peter, for it was enough that Peter had been corrected by popular reproof and Paul’s open accusation. But it is profitable and extremely requisite for this letter. He has two reasons for relating the incident. First, his own gospel was not reproved, and he himself, when he reproved Peter, heard no reproof from Peter. Next, this too, as I said, was extremely pertinent: it is because the Galatians thought that they needed to add to the principles of the gospel to obtain life … that this letter is being written to them. Hence it is very good to tell the story, because it is this very fault that was reproved by Paul in Peter and by the people also. In this way it follows that the Galatians too are sinning. –.