Galatians 2:3 But neither Titus, who was with me, being a Greek, was compelled to be circumcised:
4 And that because of false brethren unawares brought in, who came in privily to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage:
5 To whom we gave place by subjection, no, not for an hour; that the truth of the gospel might continue with you.
In theses verses we it tells us that Titus,being a Greek, was not circumcised and according to the gospel Paul was preaching he did not have to be to be saved. But the ones proclaiming to Christians was saying he needed to be because of the Jewish law. These false believers came in secretly to spy on the gospel Paul was preaching hoping to catch him in false teaching so they could lock him up. But Paul stood his ground because he had been confirmed by Peter and the other church leaders as teaching the true Gospel which did not adhere to all the Jewish laws.The trouble makers wanted to keep the law operating in church but Paul held his ground against them. We can learn from this that sometimes when we get new converts we need to make sure they do not get led astray by trouble makers in our churches today.