Thematic Bible: Necessity of, denied by paul

Yet even my companion, Titus, though a Greek, was not compelled to be circumcised. But, on account of the false Brothers who had stolen in, the men who had crept in to spy upon the liberty which we have through union with Christ Jesus, in order to bring us back to slavery-- Why, we did not for a moment yield submission to them, that the Truth of the Good News might be yours always!