Romans 2:25, 28, 29

Circumcision has value if you observe the law, but if you break the law, you have become as though you had not been circumcised.

A person is not a Jew who is one only outwardly, nor is circumcision merely outward and physical.

No, a person is a Jew who is one inwardly; and circumcision is circumcision of the heart, by the Spirit, not by the written code. Such a person’s praise is not from other people, but from God.