John Calvin Commentary 2 Peter 2:18

"For, uttering great swelling [words] of vanity, they entice in the lusts of the flesh, by lasciviousness, those who are just escaping from them that live in error;" — 2 Peter 2:18 (ASV)

For when they speak great swelling words of vanity. He means that they dazzled the eyes of the simple with high-flown language, so that they might not perceive their deceit, for it was not easy to captivate their minds with such foolish notions unless they were first deceived by some trickery. He then says that they used inflated language and speech, so that they might fill the unwary with admiration. And then this grandiloquence, which the ample lungs of the soul send forth (as Persius says), was very suitable to cover their tricks and deceptions.

There was previously a craft of this kind in Valentinus, and in those like him, as we learn from the books of Irenaeus. They coined previously unheard-of words, by whose empty sound the unlearned were struck, and thus they were ensnared by their fantasies.

There are fanatics of a similar kind today, who call themselves by the plausible title of Libertines or free-men. For they talk most confidently of the Spirit and of spiritual things, as though they roared out from above the clouds, and fascinate many by their tricks and wiles, so that one might say that the Apostle has correctly prophesied of them. For they treat all things jokingly and mockingly; and though they are utter fools, yet as they indulge in all vices, they find favor with their own people by a sort of comical antics. The state of the case is this: when the difference between good and evil is removed, everything becomes lawful, and men, released from all subjection to laws, obey their own lusts. This Epistle, therefore, is very suitable to our age.

They allure, or bait, through the lusts of the flesh. He strikingly compares to hooks the allurements of the ungodly, when they make anything they please lawful. For as the lusts of men are headstrong and craving, as soon as liberty is offered, they seize it with great eagerness; but soon afterwards the strangling hook within is perceived. But we must consider the whole sentence of the Apostle.

He says that those who had truly escaped from the company of those in error were again deceived by a new kind of error, even when they were given free rein for the indulgence of every sort of intemperance. By this, he reminds us how dangerous the wiles of these men are. For it was already a dreadful thing that blindness and thick darkness possessed almost all mankind. It was, therefore, in a way a twofold shocking event that men, freed from the common errors of the world, after having received the light of God, should be brought back to a beastly indifference.

Let us be reminded of what we should especially beware of after having been once enlightened: namely, that Satan might entice us under the pretense of liberty, so that we give ourselves up to lasciviousness to gratify the lusts of the flesh. But those who seriously attend to the pursuit of holiness are safe from this danger.