“If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, but only a fearful expectation of judgment and of raging fire that will consume the enemies of God. Anyone who rejected the law of Moses died without mercy on the testimony of two or three witnesses. How much more severely do you think a man deserves to be punished who has trampled the Son of God under foot, who has treated as an unholy thing the blood of the covenant that sanctified him, and who has insulted the Spirit of grace? For we know him who said, ‘It is mine to avenge; I will repay,’ and again, ‘The Lord will judge his people.’ It is a dreadful thing to fall into the hands of the living God.”          —Hebrews 10:26-30 NIV

“Brothers, if someone is caught in a sin, you who are spiritual should restore him gently. But watch yourself, or you also may be tempted.  . . . Do not be deceived: God cannot be mocked. A man reaps what he sows. The one who sows to please his sinful nature, from that nature will reap destruction; the one who sows to please the Spirit, from the Spirit will reap eternal life.”     —Galatians 6:1-8 NIV

“‘I am the vine; you are the branches. If a man remains in me and I in him, he will bear much fruit; apart from me you can do nothing. If anyone does not remain in me, he is like a branch that is thrown away and withers; such branches are picked up, thrown into the fire and burned.’”        —John 15:5-6 NIV

“You will say then, ‘Branches were broken off so that I could be grafted in.’ Granted. But they were broken off because of unbelief, and you stand by faith. Do not be arrogant, but be afraid. For if God did not spare the natural branches, he will not spare you either.  Consider therefore the kindness and sternness of God: sternness to those who fell, but kindness to you, provided that you continue in his kindness. Otherwise, you also will be cut off.” —Romans 11:19-22 NIV

“It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the word of God and the powers of the coming age, if they fall away, to be brought back to repentance, because to their loss they are crucifying the Son of God all over again and subjecting him to public disgrace. . . . Even though we speak like this, dear friends, we are confident of better things in your case—things that accompany salvation.” —Hebrews 6:4-9 NIV 

“For, uttering great swelling words of emptiness, they entice in the lusts of the flesh, by licentiousness, those who are indeed escaping from those who live in error; promising them liberty, while they themselves are bondservants of corruption; for a man is brought into bondage by whoever overcomes him.  For if, after they have escaped the defilement of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in it and overcome, the last state has become worse for them than the first.  For it would be better for them not to have known the way of righteousness, than, after knowing it, to turn back from the holy commandment delivered to them.  But it has happened to them according to the true proverb, ‘The dog turns to his own vomit again,’ and ‘the sow that has washed to wallowing in the mire.’” —2 Peter 2:18-22