Galatians 5:2 - Matthew Poole's English Annotations on the Holy Bible

It is manifest that the apostle is speaking here concerning circumcision, looked upon as necessary to justification, now under the gospel state. For under the Old Testament undoubtedly Christ profited the fathers, though circumcised; yea, Christ undoubtedly profiled Timothy, even under the gospel, though he was circumcised, Acts 16:3, that being done to prevent a scandal, and during a time whilst, for the gaining of the Jews to the Christian faith, the Jewish ceremonies, though dead, were (as it were) kept above ground, unburied for a time. But for men, after a sufficient time indulged them for their satisfaction concerning the abolition of the ceremonial law, still to adhere to it, and religiously to observe the rites of it, as in obedience to a Divine precept, and as necessary, over and above faith in Christ for justification, was indeed to deny Christ, and disclaim his sufficiency to save, who is able to save to the utmost them that come to God by him, Hebrews 7:25; and besides whom there is no name given under heaven, by which men can be saved, neither is there salvation in any other, Acts 4:10,12; and who is the end of the law for righteousness to every one that believeth, Romans 10:4. So that to join any thing with Christ, and faith in him, for the justification of the soul before God, is plainly to deny and disclaim him, and to make him insignificant to us. This Paul affirms with an apostolical authority and gravity: I Paul say unto you.