Having just discussed the origin of prophecy (cf. 1:19-21), Peter introduces the topic of false teachers. Just like there were those who falsely claimed to be prophets of God, there will be those who falsely claim to be teachers of His word. These false teachers Peter warns about will crop up among the brethren. They will be those who have apostatized from the truth, and as a result deny Christ.

Later he will discuss their depravity in more detail (cf. 2:12-17), but here notes that they bring destruction upon themselves. The heresies which they bring speak of liberty, but are in fact destructive. Sadly, many will be deceived, and “follow their destructive ways.” By claiming to follow Christ when actually following a heresy they blaspheme the truth.

Peter, seeking to steer his readers away from the false teachers, shows their true nature. They are merely greedy individuals who trade in men and women for their own pleasure. God has already judged such character, and actions as deserving of everlasting destruction. While they mock saying “Where is the promise of His coming?” (3:3) their destruction is on its way.