Galatians 5:3

Yea, I testify again to every man that receiveth of circumcision, that he is a debtor to do the whole law. [The apostle here gives the reason for what he has said in the previous verse. Circumcision was, in its symbolic significance, an entrance into covenant relations with God under the terms of the old covenant, and as that covenant embraced not a part, but the whole law, the covenantee, or circumcised person, was obliged to observe the whole law, or forfeit his claims to life. Paul had probably fully explained this fact on one of his previous visits, and so he now reiterates it.]