The proverb of the dog returning to its vomit (II Peter 2:18-22) describes people who have escaped the world's pollutions through knowledge of Christ but are entangled and overcome by them again, so that their latter end is worse than their beginning. False teachers allure them with deceitful ploys, promising liberty and unrestrained indulgence of the flesh while themselves being slaves of corruption. Those addicted to vice may seem interested in religion and temporarily abandon sinful practices, but seductive influences draw them back into former habits, like the dog to its vomit and the washed sow to the mire. Reformation succeeds only through total abstinence from whatever spiritually intoxicates, since a little indulgence is enough to lead those barely hanging on back into old practices. Returning is worse than never knowing the way of righteousness, because it means turning from the holy commandment. This does not necessarily mean such people were true Christians who had grieved the Holy Spirit, for people may outwardly reform without having the Spirit. As an example, many who left the Worldwide Church of God when it fell apart simply went back into the world. The warning fits the larger theme that escaping sin requires continual effort to overcome, along with reverence and godly fear.

Peter's proverb, "A dog returns to his own vomit, and a sow, having washed, to her wallowing in the mire," describes those who are rescued from sin through the knowledge of the Lord and Savior Jesus Christ and then plunge back into their former behaviors. Such people are slaves of corruption, for by whatever a person is overcome, by that he is brought into bondage. Once they have escaped the world's pollutions and are again entangled and overcome, their latter end is worse than their beginning. It would have been better never to have known the way of righteousness than to turn from the holy commandment after knowing it. God grants second, third, and many more chances, but they carry strings: repentance and real change. Those who beg for another chance in a crisis often revert to old habits once the danger passes, like a man who bargains with God and then lets his pledge shrink to nothing, or a deathbed penitent who recovers and returns to destructive ways. Hebrews 6 and 10 give parallel warnings that deliberately continuing in sin after receiving the knowledge of the truth leaves only a fearful expectation of judgment. Hezekiah squandered his extra years through pride, while Manasseh made the most of his second chance. God's mercy is infinitely greater than ours, yet no one should press his luck. Anyone given another chance must follow through by truly repenting and not squandering it.