Commentaries:
The source of false doctrine is demonic. Paul is writing of men who listen to, consider, follow, and then teach doctrines twisted from their biblical base (II Peter 3:16). He adds in II Corinthians 11:13-15 that, though the false doctrine comes through a man, the real source is Satan. The man is just a servant.
John W. Ritenbaugh
Damnable Heresies
The Greek word planos, translated as "deceiving" (NKJV) or "seducing" (KJV), is the same word from which we derive the English word "planet." It conveys the idea of wandering. To the astronomers of ancient Greece, the planets appeared to wander in a heaven populated by other, relatively fixed lights. Thus, evil spirits induce people to wander from the true path of God's Word. These are the principalities and powers against which we wrestle (Ephesians 6:10-12).
John W. Ritenbaugh
Damnable Heresies