II Peter 2:21-22.
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.
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.
God’s words at the end of this chapter, coming to us through Peter, are harsh. Some people would like to erase such words from scripture, keeping only the words of love, grace, and mercy.
We forget that God is holy, and cannot even look on sin. It is an abomination to His character, not to be tolerated.
If you have ever owned a dog, you know the truth that when a dog vomits, he will go back and eat it up again. And pigs like to stay cool, so no matter how clean they may be, they will find a nice, cool mud puddle in which to relax. These are not pretty pictures, but they are truth.
In verse 21, Peter wrote that it would be better for a person never to have known truth than to know it and turn away from it, going back to that which is untrue and even evil.
We are responsible to God for our choices. There will be no arguing or debating at the time of judgment. Those who have known truth and chosen to turn away from it will pay the penalty for doing so. No excuses. The time of grace and mercy, for them, will be gone. Forever. No turning back.