It is not entirely clear exactly what these false teachers would have said. Clearly they must have spoken with an assertive confidence that makes people think they know what they are talking about.1 Peter could be referring to their arrogant and boastful speech in terms of slandering glorious ones or celestial beings (2 Peter 2:10).2 Alternatively it could be a reference to their claims that there is no coming judgment, thereby encouraging their followers to return to the morally lax ways of pagan society.3
18 For, speaking loud boasts of folly, they entice by sensual passions of the flesh those who are barely escaping from those who live in error.