‘For in Christ Jesus neither circumcision avails anything, nor uncircumcision, but faith working through (or ‘by') love.'
For in Christ it matters not whether a person is circumcised or uncircumcised. Circumcision makes no difference to a man's inner life. What matters is faith working in response to the love of Christ, or faith expressing itself in love. Thus circumcision itself is unimportant. It is the attitude of a person's heart that matters, not whether he is physically circumcised. What matters is to be circumcised in heart (Romans 2:29; Philippians 3:3; Colossians 2:11).
The love that results from faith is the perfect answer to those who react to Paul's teaching by saying that he gives men licence to behave as they like. For love fulfils all God's requirements (Galatians 5:13-14).
It should be noted here that all this does not mean that rules are necessarily a bad thing, nor indeed that the Law was a bad thing. As a guide for living and as a guide for knowing the mind of God they may be excellent. But where they become wrong, and indeed unchristian, is when they are used as a means of becoming acceptable to God, as a means of putting men ‘in the right' with God. Or even as a means of making them somehow superior to other Christians. That is legalism, and Paul in Galatians condemns it out of hand.
When we ‘dechristianise' people on the grounds that they do not keep the Sabbath, or do not experience special experiences that we experience, or do not observe certain regulations that we have decided are important, we share in the condemnation that Paul pours on the Judaisers. We may to some extent be right about the importance of such things to us, but we are wrong if we make them determining factors about somebody's Christian status. The only test of that is their faith in the crucified and risen Christ.