Behold, I Paul say unto you, that if ye be circumcised, Christ shall profit you nothing.
Note 6 at Ga 5:2: Paul was circumcised himself (Php 3:5), so what was he saying? Paul was referring to trusting in some external action to produce justification with God instead of just faith in Christ. The false teachers in Galatia had taught that circumcision (see note 2 at Ac 15:1) and the keeping of the Old Testament Law were necessary for salvation.
It doesn't matter if it is circumcision, water baptism, holiness, or any other religious act; trust in anything except Christ voids the saving effects of Christ in our lives (see note 16 at Ga 2:21).
A simple way to detect what our faith is in is to imagine ourselves standing before God, giving a reason that we should be allowed into heaven. If we pointed out our church attendance, giving receipts, acts of holiness, or anything else, then that is what our faith is in. Those of us who would do that are no different than Muslims or Buddhists. We would be trusting in our own efforts to produce salvation.
The proper response would be to say, "The only thing that makes me worthy to enter heaven is what Jesus did for me. My total faith and trust is in Jesus." It's not Jesus plus anything (see note 2 at Ro 11:6). Faith alone saves (see note 2 at Joh 3:3).
Note 7 at Ga 5:2: The phrase "Christ shall profit you nothing" is another way of saying that if people turn to self-effort for salvation, then they cannot benefit in any way from what Christ has done for them. The only way to appropriate what Jesus did for man is by faith.
It is possible to put total faith in Jesus concerning our eternal salvation and yet turn back to the deception that God will only bless us in this life proportionally to our performance. That is not true and will keep us from experiencing the abundant life Jesus purchased for us (Joh 10:10).