Romans 2:25, 28-29

For circumcision indeed is of value if you obey the law, but if you break the law, your circumcision becomes uncircumcision.

For no one is a Jew who is merely one outwardly, nor is circumcision outward and physical. But a Jew is one inwardly, and circumcision is a matter of the heart, by the Spirit, not by the letter. His praise is not from man but from God.