Galatians 2:3

3. Neither Titus… circumcised Titus is here put forth as a living fact in proof of what the pillars did not require. He was placed by St. Paul among them as an uncircumcised Gentile Christian, and they yield the point of circumcision. Paul, according to his ground, could circumcise his Gentile converts, as he did Timothy, if expedient, without any surrender of the principle. But they could not accept one uncircumcised Christian without admitting that there could be Christianity without circumcision. We can, therefore, clearly see why Paul could circumcise Timothy and insist that Titus should not be circumcised. And Paul, doubtless, puts this case to the Galatians as an answer to the argument drawn from his circumcising Timothy.