2 Peter 2:21-22 NIV

21 It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them.1

References for 2 Peter 2:21

22 Of them the proverbs are true: "A dog returns to its vomit,"a2 and, "A sow that is washed goes back to her wallowing in the mud."

References for 2 Peter 2:22