17 These people are springs without water, mists driven by a whirlwind. The gloom of darkness has been reserved for them. 18 For by uttering boastful, empty words, they seduce, with fleshly desires and debauchery, people who have barely escaped from those who live in error. 19 They promise them freedom, but they themselves are slaves of corruption, since people are enslaved to whatever defeats them. 20 For if, having escaped the world’s impurity through the knowledge of our Lord and Savior Jesus Christ, they are again entangled in these things and defeated, the last state is worse for them than the first. 21 For it would have been better for them not to have known the way of righteousness than, after knowing it, to turn back from the holy command delivered to them. 22 It has happened to them according to the true proverb: A dog returns to its own vomit, and, “a sow, after washing itself, wallows in the mud.”
Peter is warning against false teachers. Proverbs 10:11 says: “The mouth of a righteous man is a well of life: but violence covereth the mouth of the wicked.” According to Douglas Moo, “The dry Mediterranean climate, with long stretches of land and little water, rendered fresh water springs essential to life. As useless and dangerous as springs without water is the teaching of these false Christians.” These “mists” or clouds promise rain, but don’t deliver, just as false teaching promises life, but leads to death.
Jude says the same as Peter does about the words of false teachers: These people are discontented grumblers, walking according to their desires; their mouths utter arrogant words, flattering people for their own advantage.”
The severity of punishment in Hell will be different for each individual, depending on his opportunity at godly knowledge as it corresponds to his utilization of it. For those who have heard the message of the gospel, yet reject it, there is reserved for them a greater “gloom of darkness.” Along with this, James says that “not many should become teachers, my brothers, knowing that we will receive a stricter judgment.” And as Mark records Jesus saying, “But whoever causes the downfall of one of these little ones who believe in Me—it would be better for him if a heavy millstone were hung around his neck and he were thrown into the sea.” “[Peter] was clearly concerned about those masquerading in religious garb who were leading astray new converts.”
All three of the above judgments can be made on false teachers. Their judgment will be severe - and not only in eternity, but also on earth, for Matthew 12 says: 43 “When an unclean spirit comes out of a man, it roams through waterless places looking for rest but doesn’t find any. 44 Then it says, ‘I’ll go back to my house that I came from.’ And returning, it finds the house vacant, swept, and put in order. 45 Then off it goes and brings with it seven other spirits more evil than itself, and they enter and settle down there. As a result, that man’s last condition is worse than the first.”
Let this be a warning to those who teach as well as to laypeople. Teach with the fear of the Lord determining your speech and listen with a carefulness not to accept anything that does not match up with the Word of God.