Surprised me some. There were signs.
They just couldn't help themselves.
What they really think and believe will eventually become manifest in their decisions and outward behavior.
"Past behavior predicts future behavior.." Consistent patterns of specific past actions are strong predictors of future actions, though it's not foolproof cuz they could repent and get saved. That's why the police, when they pull someone over asks: Have you been arrested and what have you been arrested for?
There is a sobering reality Scripture never softens: when a person remains unregenerated, unchanged at the core, they cannot sustain righteousness by willpower alone. They may improve their behavior for a season. They may adopt religious language, attend church, and even appear sincere. But without a new heart, the old nature eventually reasserts itself. When truth is resisted long enough, the heart hardens, the conscience dulls, and the soul drifts back toward what feels familiar.
The Apostle Peter captures a tragic yet typical cycle with unflinching honesty:
“What the true proverb says has happened to them: ‘The dog returns to its own vomit, and the sow, after washing herself, returns to wallow in the mire’” (2 Peter 2:22, ESV).
Please repent/change - ask Christ to forgive you and come in. Please walk with and know God’s Word intimately, and exercise discernment when you hear their impressive language (v. 18) and alluring promises (v. 19). They fellowship with you only to find out what they can get from you (vv. 12–14), and then they will leave you in worse shape than they found you. They are deceptive and destructive, so beware!
Their purpose is personal pleasure and financial gain, and their destiny is judgment. Like Balaam (Num. 22–24), they cause others to sin by using religion for personal gain. They are not God’s sheep; they are pigs and dogs in sheep’s clothing (Prov. 26:11; Matt. 7:15) and eventually go back to their natural habits. True sheep keep themselves clean because they follow the Shepherd (John 10:27–28).
The imagery is deliberately unsettling because the reality is. A washed sow does not become a sheep. No amount of external cleansing alters its nature. Before long, it returns to the mud, and anyone who has seen a pig wallow knows what that mud contains.
Peter is doing what the apostles often did. He draws from familiar proverbs to make spiritual truth unavoidable. The first saying comes directly from Scripture: “As a dog returns to his own vomit, so a fool repeats his folly” (Proverbs 26:11, NKJV). The second proverb, while not preserved elsewhere in the Old Testament, was almost certainly a well-known saying in the first century. Peter uses both to conclude his warning against false teachers and the devastation they leave behind.
The point is not insult for insult’s sake. The point is nature. Behavior follows being.
These false teachers had proximity to truth without submission to it. They had heard the gospel, understood the language of discipleship, and even escaped certain outward corruptions for a time. “They have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ” (2 Peter 2:20). But knowledge alone did not regenerate them. Without repentance and new birth, they were “again entangled in them and overcome” (2 Peter 2:20), ending in a condition worse than where they began.
“It would have been better for them not to have known the way of righteousness,” Peter writes, “than after knowing it, to turn back from the holy commandment delivered to them” (2 Peter 2:21).
A sow can be washed even if he's dressed to the nines in a designer tuxedo.. it cannot be changed.
Scripture consistently distinguishes between sheep and impostors, not by momentary reform, but by inward transformation. Jesus never referred to His people as dogs or pigs. He called them sheep. Sheep may stumble into mud, but they do not love it. They do not feel at home there. They long to be clean again.
That difference matters.
Church attendance, religious vocabulary, and moral effort have value, especially in gospel-faithful communities. But none of these confer new life. As Jesus said plainly, “You must be born again” (John 3:7). Or as Paul put it, “If anyone is in Christ, he is a new creation” (2 Corinthians 5:17). Christianity is not behavior modification. It is resurrection.
C.S. Lewis once observed, “No man knows how bad he is till he has tried very hard to be good.” That truth plays out painfully in 2 Peter 2. These men tried religion without repentance, reform without surrender, knowledge without obedience. Like many religious people, they possessed intellectual familiarity with Christ but never bowed to Him as Lord (Romans 10:1–4). They refused His call: “If anyone wants to follow after me, let him deny himself, take up his cross daily, and follow me” (Luke 9:23, CSB).
So they returned.
Back to the muddy mire.
Back to the vomit.
Peter explains that they had rejected “the holy commandment delivered to them” (2 Peter 2:21, ESV), shorthand for the full counsel of God’s Word. Having turned from the truth, they resumed what was vile and destructive, like a dog revisiting what should repel it.
To modern readers, the imagery can feel harsh. Dogs today are companions. But in the ancient world, dogs were despised scavengers, roaming in packs, feeding on refuse and decay. Scripture consistently portrays them as unclean and dangerous (Exodus 22:31; 1 Kings 14:11; Jeremiah 15:3; Psalm 22:16). Jesus Himself used dogs and pigs as metaphors for those who mock and trample sacred truth (Matthew 7:6; 15:26–27). Paul echoed the warning: “Watch out for those dogs, those evildoers” (Philippians 3:2).
Peter’s conclusion is chilling but precise. These false teachers were not merely mistaken. They were unrepentant. They were not sheep who wandered. They were “brute beasts made to be caught and destroyed,” speaking “evil of the things they do not understand,” and destined to “utterly perish in their own corruption” (2 Peter 2:12, NKJV).
And yet, this passage is not written to terrify true believers. It is written to clarify.
Second Peter 1:5–11 reminds us that perseverance marks genuine faith. False teachers will always infiltrate the church (Matthew 24:11, 24; Acts 20:29–30; Galatians 1:6–9; 1 John 2:18–19). Some will look authentic. Some will sound convincing. Jesus warned that not everyone who says “Lord, Lord” belongs to Him (Matthew 7:21–23).
So the practical application is personal before it is polemical.
Every professing Christian must ask: Am I trusting in Christ alone, or am I trusting in my own self-confident reform? Assurance rests not in good intentions, but in the finished work of Jesus. Regeneration shows itself over time, not in perfection, but in direction. New affections emerge. Love grows. Obedience becomes willing. Truth becomes precious. Sin becomes bitter.
Sheep may fall. They do not feast in filth.
Many believers can testify that when they drift into sin, joy drains away. Conviction sets in. Restoration becomes urgent. And when fellowship is renewed, it feels like waking to clear skies after a storm.
Augustine said it well: “You have made us for Yourself, O Lord, and our hearts are restless until they rest in You.”
So heed the warning, but do not miss the grace beneath it. Do not be content with a washed exterior. Seek a changed heart. Beware of teachers whose lives contradict their words. As Jesus said, “You will recognize them by their fruits” (Matthew 7:16). And remember this:
Dogs return to vomit.
Pigs return to mud.
But sheep follow the Chief Shepherd.
By the grace of God and the power of the Holy Spirit, those truly born again will press on in faith, endure to the end, and inherit eternal life (Matthew 24:13; John 15:4–10; Hebrews 3:14; James 1:12; 2 Peter 3:11–18; 2 Timothy 4:7–8).
That is not moral optimism.
It is gospel certainty.
Peter’s closing line in 2 Peter 2:22 is deliberately framed as “the true proverb,” yet it is actually a pair of sayings drawn from different streams of wisdom, joined to make a single, devastating point.
“But it happened unto them according to the true proverb,
The dog is turned to his own vomit again;
and the sow that was washed to her wallowing in the mire”
(2 Peter 2:22, KJV).
The first half is easy to trace. Peter is directly quoting Scripture:
“As a dog returneth to his vomit, so a fool returneth to his folly”
(Proverbs 26:11, KJV).
The second half, however, does not appear anywhere else in the Old Testament. That has led some readers to wonder whether Peter was inventing imagery. He was not. Rather, he was doing something very common among Jewish teachers and early Christian apostles: weaving together biblical wisdom with well-known proverbial sayings that his audience would instantly recognize.
As Michael Green explains this, Peter ends this fierce chapter “with two proverbs which aptly describe the situation of the false teachers.” Their judgment is not arbitrary. “Their punishment is that they will be given over to the lot they have chosen.” Green adds this sobering line: “The awfulness and irrevocability of hell lies just here; God underwrites a man’s deliberate choice. In the end we all go ‘to our own place.’”
That thought echoes Scripture itself. Judas, after his betrayal, is said to have gone “to his own place” (Acts 1:25). Paul warns that those who suppress the truth are eventually “given over” to what they desire (Romans 1:24–28). Judgment, in this sense, is not God forcing something alien upon a person, but confirming the direction they have persistently chosen.
Green’s explanation of the imagery is especially vivid and pastoral. The dog which has gotten rid of the corruption inside it through vomiting it up cannot leave well alone; it goes sniffing round the vomit again. The pig that has got rid of the corruption outside it by means of a scrubbing cannot resist rolling in the mud.” The distinction matters. The dog’s problem is internal. The pig’s problem is external. Neither has experienced a change of nature.
I'm not a Calvinist, but Mr. Calvin pressed the same point with gospel clarity:
“The gospel is a medicine that purges us as a wholesome emetic, but there are many dogs who swallow again what they have brought up, to their own ruin. Likewise the gospel is a basin which cleanses us from all our dirt and stains, but there are many pigs who, immediately after they have washed, roll back again into the mud.”
This is precisely what Peter has been describing throughout the chapter. These false teachers had escaped certain outward corruptions through exposure to Christ’s truth, yet without repentance and new birth, they were “again entangled” and overcome (2 Peter 2:20). Reform touched their behavior, not their hearts.
As for the origin of the proverb about the sow, Green notes that while it is not biblical in the strict sense, it was almost certainly drawn from a popular collection of sayings circulating in the ancient world. A close parallel appears in the Syrian story of Ahikar, which existed by at least the second century BC and was widely known. In that account, the proverb runs:
“My son, thou hast been to me like the swine that had been to the baths, and when it saw a muddy ditch, went down and washed in it, and cried to its companions, ‘Come and bathe.’”
The resemblance is unmistakable. Peter is not proof-texting folklore. He is harnessing a familiar image to drive home a biblical truth already established throughout Scripture: cleansing without conversion never lasts.
Even the language Peter chooses reinforces the severity of the picture. The word borboros, “mire,” is rare and poetic. In the Greek Old Testament it appears only in Jeremiah 45:6, describing the filth of Jeremiah’s prison. Later Christian writings use it for the filth of hell itself. Likewise, Peter’s terms for “vomit” and “wallowing” are strikingly graphic and appear nowhere else in the New Testament. The Holy Spirit is not being subtle here.
All of this fits seamlessly with Jesus’ own teaching. Our Lord joined dogs and pigs together as symbols of those who are hostile to holy things: “Do not give dogs what is holy, and do not throw your pearls before pigs” (Matthew 7:6). To a Jewish audience, both animals were unclean. Paul uses the same imagery when warning against false teachers: “Beware of dogs, beware of evil workers” (Philippians 3:2).
Peter’s point, then, is not that true believers never sin. Scripture is clear that sheep may stumble (Psalm 37:24; 1 John 1:8–9). The point is that sheep do not love the mud. They do not return to it as home. False teachers, by contrast, reveal their nature over time. Like the dog and the sow, they return willingly, instinctively, and repeatedly to what should revolt them.
In the end, 2 Peter 2:22 is about spiritual reality. Nature reveals destiny. As Jesus said, “A good tree cannot bear bad fruit, nor can a bad tree bear good fruit” (Matthew 7:18).
“Where the heart goes, the life follows.” ~ Augustine
Peter calls these sayings “true proverbs” because they tell the truth about the human heart apart from regeneration.
External washing..even religious or water baptism alone.. is not enough. Only a new heart from a real rebirth can keep a person from returning to what once enslaved them (sanctification begins inside): “I will give you a new heart and put a new spirit within you” (Ezekiel 36:26).
Anything less leaves a man, in the end, going back to his own place. Don't go backwards. Go to God the Son with true repentance.
