Solomon warns, “As a dog returns to his own vomit, so a fool repeats his folly” (Prov. 26:11). Why would a dog return to his vomit? It doesn’t seem “natural”—surely we wouldn’t do it. But that is precisely the point: character counts! What comes “naturally” to a dog “naturally” repels cats. And it comes naturally to a fool to be foolish.
Where does character come from? The Bible places strong emphasis on the power of habit: We are warned to shun those who are given to a habit of drunkenness (Prov. 23:35), a hot temper (Prov. 19:19), or flattery (Prov. 20:19)—because “the companion of fools will be destroyed” (Prov. 13:20). Jeremiah underscores the point: “Can the Ethiopian change his skin or the leopard its spots? Then may you also do good who are accustomed to do evil” (Jer. 13:23).
What kind of company you keep will tend to determine your character—and, in turn, that character will attract the company you keep: “He who walks with wise men will be wise, but the companion of fools will be destroyed” (Prov. 13:20). St. Paul warned, “Do not be deceived: evil company corrupts good habits” (1 Cor. 15:33). To put it another way, he said, “a little leaven leavens the whole lump” (1 Cor. 5:6).
Centuries later, the Apostle Peter shot Solomon’s arrow home with a blistering attack against evil, deceptive teachers within the church who sought to seduce believers into apostasy: “For if, after they have escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and overcome, the latter end is worse for them than the beginning.… But it has happened to them according to the true proverb: ‘A dog returns to its own vomit,’ and ‘A sow, having washed, to her wallowing in the mire’ ” (2 Peter 2:20–22).
Peter sets up a subtle contrast between two words that are similar in form, but radically different in substance—pollution and corruption. In the first chapter of this letter, he had encouraged his readers with the assurance that God has made us “partakers of the divine nature, having escaped the corruption that is in the world through lust” (2 Peter 1:4). That word corruption means “rottenness,” an internal, progressive decay, like a cancer—but this deadly disease Christians have escaped. While “the whole world lies under the sway of the evil one” (1 John 5:19), we have been “freed from sin,” no longer under sin’s dominion (Rom. 6:7–14).
But what about the distressing fact that often apparently Christian people, and even famous “Christian leaders,” have turned out to be traitors: Judas was the first, but certainly not the last. Jesus Himself issued the fearful warning: “By their fruits you will know them. Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven, but he who does the will of My Father in heaven” (Matt. 7:20–21).
This is illustrated by the incident in which Jesus washed His disciples’ feet (John 13). Peter protested, saying, “You shall never wash my feet!” Jesus surprised him: “Unless I wash you, you have no part with me.” Peter misunderstood again, and blurted out: “Lord, not just my feet but my hands and my head as well!” Again, Jesus’ response surprised him: “A person who has had a bath needs only to wash his feet; his whole body is clean. And you are clean, though not every one of you.” St. John makes the editorial comment: “For He knew who was going to betray Him, and that was why He said not every one was clean.”
There is an ironic, dramatic contrast here: Judas was externally “clean,” since Jesus had washed his feet: but inwardly, he was on the verge of such a vicious betrayal that Christ Himself soon called him the frightening term “the son of perdition” (John 17:12)—a term indicating utter ruin and eternal destruction (see Matt. 7:13; Rom. 9:22). On the other hand, Peter was externally “dirty,” but was a true child of God: “clean” on the inside, because his sins had been forgiven.
Christians are daily walking through a “dirty” world (Rom. 3:23; Eccl. 7:20). Yet we are not under any necessity to sin; we have the divine ability to resist the devil successfully (James 4:7).
Toward the end of this letter, St. Peter gives the punchline: although these false teachers “have escaped the pollutions of the world,” yet nevertheless they “are slaves of corruption” (2 Peter 2:19)—the very same “corruption” that true Christians have escaped (v. 1:4)!
What makes a dog eat her own vomit? Because she’s a dog; she does it in order to regurgitate and feed her pups. What makes a sow wallow in the mire? Because it’s her nature to do so; she doesn’t have sweat glands, and is unable to cool off without doing what most of us would consider distasteful. We can clean her up, put a pretty pink bow on her, and spray her with cologne, but her external cleanliness doesn’t change her fundamental nature one whit. Animals—and people—act according to their natures. By their fruits you shall know them.
