For circumcision indeed profiteth, if thou be a doer of the law: but if thou be a transgressor of the law, thy circumcision is become uncircumcision.

It is true that circumcision is of use if you keep the law, but if you go against the law it is as if you had it not.

Επειδη ωφελει μεν η περιτομη, εαν εκτελης τον νομον· εαν ομως ησαι παραβατης του νομου, η περιτομη σου εγεινεν ακροβυστια.

For circumcision verily profiteth, if thou keep the law: but if thou be a breaker of the law, thy circumcision is made uncircumcision.