2 Peter 2:20-22

20For if, having escaped the world’s impurity through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in these things and defeated, the last state is worse for them than the first.

21For it would have been better for them not to have known the way of righteousness than, after knowing it, to turn back from the holy command delivered to them.

22It has happened to them according to the true proverb: A dog returns to its own vomit, and, “A washed sow returns to wallowing in the mud.”