Galatians 2:3
But not even Titus who was with me, being a Greek, was made to undergo circumcision:
Acts 16:3
Paul had a desire for him to go with him, and he gave him circumcision because of the Jews who were in those parts: for they all had knowledge that his father was a Greek.
Acts 15:24
Because we have knowledge that some who went from us have been troubling you with their words, putting your souls in doubt; to whom we gave no such order;
1 Corinthians 9:20-21
And to the Jews I was as a Jew, so that I might give the good news to them; to those under the law I was the same, not as being myself under the law, but so that I might give the good news to those under the law.
2 Corinthians 2:13
I had no rest in my spirit because Titus my brother was not there: so I went away from them, and came into Macedonia.
Galatians 5:2-6
See, I Paul say to you, that if you undergo circumcision, Christ will be of no use to you.