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
John Chrysostom
AD 407
He was not afraid of his own endangerment; for one who had no fear at the beginning would have all the less at that time. Rather, he feared their apostasy. Just as Paul himself says to the Galatians, “I am afraid I have labored over you in vain.”