You are severed from Christ, you who would be justified by the law; you have fallen away from grace.
(Galatians 5:4 ESV)
Here's the whole passage - we can replace circumcision (not really something from the law we get strict about in our own day) with an issue from the law that we get in a tizzy about in our day.
"For freedom Christ has set us free; stand firm therefore, and do not submit again to a yoke of slavery.
Look: I, Paul, say to you that if you accept circumcision, Christ will be of no advantage to you. I testify again to every man who accepts circumcision that he is obligated to keep the whole law. You are severed from Christ, you who would be justified by the law; you have fallen away from grace. For through the Spirit, by faith, we ourselves eagerly wait for the hope of righteousness. For in Christ Jesus neither circumcision nor uncircumcision counts for anything, but only faith working through love."
(Galatians 5:1-6 ESV)