2 Peter 2:1-5

But [in those days] false prophets arose among the people, just as there will be false teachers among you, who will subtly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction on themselves. Many will follow their shameful ways, and because of them the way of truth will be maligned. And in their greed they will exploit you with false arguments and twisted doctrine. Their sentence [of condemnation which God has decreed] from a time long ago is not idle [but is still in force], and their destruction and deepening misery is not asleep [but is on its way]. For if God did not [even] spare angels that sinned, but threw them into hell and sent them to pits of gloom to be kept [there] for judgment; and if He did not spare the ancient world, but protected Noah, a preacher of righteousness, with seven others, when He brought [the judgment of] a flood upon the world of the ungodly; [Gen 6-8; 1 Pet 3:20]