Gal 5:4 NASB
4You have been severed from Christ, you who are seeking to be justified by law; you have fallen from grace.
II Pet 2:20-22, "For if, after they have escaped the defilements of the world through the knowledge of our Lord and Savior Jesus Christ, they are again entangled in them and overcome, the last state has become worse for them than the first. For it would have been better for them never to have known the way of righteousness than after knowing it to turn back from the holy commandment delivered to them. What the true proverb says has happened to them: "The dog returns to its own vomit, and the sow, after washing herself, returns to wallow in the mire."
Rom 11
18do not be arrogant toward the branches; but if you are arrogant, remember that it is not you who supports the root, but the root supports you.
19You will say then, “Branches were broken off so that I might be grafted in.”
20Quite right, they were broken off for their unbelief, but you stand by your faith[/b]. Do not be conceited, but fear;
21for if God did not spare the natural branches, He will not spare you, either.
22Behold then the kindness and severity of God; to those who fell, severity, but to you, God’s kindness, if you continue in His kindness[/b]; otherwise you also will be cut off.
23And [b]they also, if they do not continue in their unbelief, will be grafted in, for God is able to graft them in again.