Galatians 5:3
“For I testify again to every man that is circumcised, that he is a debtor to do the whole law.”
The Apostle Paul is not speaking here of any man who is circumcised — for in today’s society circumcision is often done for medical purposes without any thought being given to the religious side of the issue. Rather, Paul was speaking of any man who was circumcised for the purposes of eternal salvation. If a man chose to be circumcised in order to help gain eternal salvation then he must also accept that he was responsible for the entire law service. The law service was a perfect and just law given by God. It was complete. Likewise, grace is complete in and of itself. A man must choose one or the other but cannot join the two together for they are not the same. Thus, any man who wished to be circumcised as the false teachers promoted in order to gain salvation must also be ready to keep the rest of the law as well.
Additional Reading
Romans 2:28-29
Thoughts and Meditations of Elder J.W. Cunningham 