“[But] there hath happened to them the [saying] of the true proverb, A dog returned to his own vomit, and A sow washed into rolling in mire” (vers. 22).
The yielding to sin, described in ver. 21, is entirely confirmed by the application to their case by the point of the true proverb that follows: “a dog returned to his own vomit, and a sow washed into rolling in mire.” Never had these evil workers been sheep of the Good Shepherd's pasture. They had never been transformed by the renewal of mind which is of God's effectual grace. There was therefore no such anomaly in the Christian sphere as the degradation of a sheep to a dog, nor such a metamorphosis as into swine. When born anew, there is a new life and nature imparted; but the old abides to be disallowed, because we died with Christ to sin. But a dog does not become a sheep, nor do sheep become swine, save in the false science of theology. “That which is born of the flesh is flesh; and that which is born of the Spirit is spirit” (John 3:6). And this it is which the believer receives through faith in Christ, even His life communicated now to the soul in the Spirit, as by-and-by to the body also at His coming again. There is not the most distant thought that the false teachers were ever thus born anew. On the contrary they are described as having no more than what the natural mind is capable of knowing. They might have accurate knowledge in the intellect, but no divine work whereby they were begotten of God. Hence at last came a turning back to a worse state than before they professed Christianity.
What can exceed the loathing our apostle feels and expresses, as he denounces not only the errors but the immoral practices of these false teachers? The apostle of the circumcision described in solemn terms the ruin of which Paul at Miletus warned the elders of the church in Ephesus. “I know that there will come in among you after my departure grievous wolves not sparing the flock; and from among your own selves shall rise up men speaking perverted things to draw away the disciples after them” (Acts 20:29, 30). “Grievous wolves” are surely enemies, whether or not they get the position of guides; they were enemies who, instead of loving and tending the flock of God, ravenously and at all cost preyed on the sheep. And the alienated elders, who forgot the Lord with the grace and truth which came through Him, fell sadly from their office when they by means of perverted things drew away the disciples after them. Thus what man built in the Lord's name, man's will should mislead and destroy; and such is Christendom, an utter departure from the heavenly witness of Christ to which the church and every Christian is called. That which Christ has built will alone stand, for it is kept through the grace that is in Him, which is unfailing. But all that bear His name are responsible; and guides must give account, not merely as all saints, but of that entrusted to them in particular.
Still these self-seeking chiefs, and even the grievous wolves though violently injurious, are not depicted with the contempt which the apostle attaches to those of whom he warns in this chapter. What figure more expressive of abominable impurity can be found to express “A dog returning to his own vomit, and A washed sow into rolling in mire?” The dog so returning we hear of in Prov. 26:11, where the application is to the fool returning to his folly. Here it is still more emphatically said of him who once knew clearly the glad tidings of Christ and the truth of God in a general way. The better the knowledge, the worse if corruption ensues. What could match it but “A washed sow” again gone back to roll in mud?
Thus the awful issue of unrenewed man here set out in the unerring word of God keeps the security of grace wholly untouched. May the true believer not slip or fall? Surely he may, unwatchful. But “he shall be made to stand; for the Lord is able to make him stand (Rom. 14:4). Without Him he owns himself lost; but now “we more than conquer through Him that loved us” (Rom. 8:37). A man may preach ever so acceptably; but if he live evilly as one not born anew, he perishes a reprobate. And why any Christian should question this is the less excusable, since scripture is perfectly plain in its call to self-denial, and in its denunciation of unholiness particularly in such as profess the Lord's name, with full warning of the awful end.