Luke 14:28-30   28. For which of you, intending to build a tower, sitteth not down first, and counteth the cost, whether he have sufficient to finish it? 29. Lest haply, after he hath laid the foundation, and is not able to finish it, all that behold it begin to mock him, 30. Saying, This man began to build, and was not able to finish.

2 Peter 2:20-22   20. For if after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled therein, and overcome, the latter end is worse with them than the beginning. 21. For it had been better for them not to have known the way of righteousness, than, after they have known it, to turn from the holy commandment delivered unto them. 22. But it is happened unto them according to the true proverb, The dog is turned to his own vomit again; and the sow that was washed to her wallowing in the mire.

Hebrews 6:4-8   4. For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, 5. And have tasted the good word of God, and the powers of the world to come, 6. If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame. 7. For the earth which drinketh in the rain that cometh oft upon it, and bringeth forth herbs meet for them by whom it is dressed, receiveth blessing from God: 8. But that which beareth thorns and briers is rejected, and is nigh unto cursing; whose end is to be burned.