Galatians 2:3-5
2:3 Yet not even Titus, who was with me, was compelled to be circumcised, although he was a Greek.
2:4 Now this matter arose because of the false brothers with false pretenses who slipped in unnoticed to spy on our freedom that we have in Christ Jesus, to make us slaves.
2:5 But we did not surrender to them even for a moment, in order that the truth of the gospel would remain with you.