Galatians 5:4

2 Peter 2:20-22 NIV
If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and are overcome, they are worse off at the end than they were at the beginning. It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them. Of them the proverbs are true: “A dog returns to its vomit,” and, “A sow that is washed returns to her wallowing in the mud.”

Galatians 2:21 NIV
I do not set aside the grace of God, for if righteousness could be gained through the law, Christ died for nothing!”

Romans 11:6 NIV
And if by grace, then it cannot be based on works; if it were, grace would no longer be grace.

Romans 9:31-32 NIV
but the people of Israel, who pursued the law as the way of righteousness, have not attained their goal. Why not? Because they pursued it not by faith but as if it were by works. They stumbled over the stumbling stone.