But before faith came, we were kept in custody under the law, being shut up to the faith which was later to be revealed. Therefore the Law has become our tutor to lead us to Christ, so that we may be justified by faith. But now that faith has come, we are no longer under a tutor. (Galatians 3:23-25)
If you have faith then you are no longer under a tutor/the Law!
The purpose of Paul's letter to the Galatians and the context of the chapter reveal the flaws in this objection.
First, Paul wrote the letter to the Galatians because some were teaching that people had to obey the Law in order to become saved (see Acts 15:1-2). In Galatians chapter 2, Paul states that "man is not justified by the works of the Law but through faith in Messiah Yeshua". Paul is not saying that we should disobey the Law. He is saying that we should not obey the works of the Law in order to be justified before God.
Second, in the passage above, Paul states that the Law has become our tutor to lead us to Messiah. It wasn't our tutor before but now it has become one. The Law has taken on an additional function: pointing us to Messiah. Once that function is complete [and we have been brought to Messiah] then it no longer performs that function. Paul does not say that the Law has no other function.