Gal. 5:2 "Behold, I Paul, say to you that if you become cir cised, Christ will profit you nothing!"
Gal. 5:3 "And I testify again to every male who receives cir cision, that he is in debt to keep the whole Law. You who do so have been severed from Christ. . . you have fallen from grace."
Phil. 3:2 "Beware of the dogs! Beware of the evil workers! Beware of the mutilation! For WE are the true cir cision, who worship in the Spirit of God, and glory in Christ Jesus, and put NO confidence in the flesh!"
Col. 2:8-14 "See to it that no one takes you captive through philosophy and empty deception, according to the tradition of men...rather than according to Christ. For in Him all the fulness of Deity dwells in bodily form and in Him you have been made whole.. and in Him you were also cir cised, with a cir cision made without hands, in the removal of the body of the flesh by the cir cision of Christ, having been buried with Him in baptism, and raised up with Him through faith. And...in the uncir cision of your flesh, He made you alive together with Him. . . having cancelled out the certificate of debt consisting of decrees against us which were hostile to us. And He has taken them out of the way, having nailed them to the cross."
And there are many other examples that I don't have time to look for, basically if you're a Christian you believe that Christ died for your sins, if you're going to seek salvation through the old law then you'd better uphold all of it.