2 Peter 2:20-22

Common(i) 20 For if, after they have escaped the defilements of the world by the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and are overcome, the last state has become worse for them than the first. 21 For it would have been better for them not to have known the way of righteousness, than having known it, to turn away from the holy commandment handed on to them. 22 It has happened to them according to the true proverb, "A dog turns back to its own vomit," and, "A sow, after having washed, returns to wallowing in the mire."