A.T. Robertson Commentary 2 Peter 2:1

"But there arose false prophets also among the people, as among you also there shall be false teachers, who shall privily bring in destructive heresies, denying even the Master that bought them, bringing upon themselves swift destruction." — 2 Peter 2:1 (ASV)

But there arose (εγενοντο δε). Second aorist middle indicative of γινομα (cf. γινετα in 1:20).

False prophets also (κα ψευδοπροφητα). In contrast with the true prophets just pictured in 1:20f. Late compound in LXX and Philo, common in N.T. (Matthew 7:15). Allusion to the O.T. times like Balaam and others (Jeremiah 6:13; Jeremiah 28:9; Ezekiel 13:9).

False teachers (ψευδοδιδασκαλο). Late and rare compound (ψευδησ, διδασκαλος) here alone in N.T. Peter pictures them as in the future here (εσοντα, shall be) and again as already present (εισιν, are, verse 17), or in the past (επλανηθησαν, they went astray, verse 15).

Shall privily bring in (παρεισαξουσιν). Future active of παρεισαγω, late double compound παρεισαγω, to bring in (εισαγω), by the side (παρα), as if secretly, here alone in N.T., but see παρεισακτους in Ga 2:4 (verbal adjective of this same verb).

Destructive heresies (αιρεσεις απωλειας). Descriptive genitive, "heresies of destruction" (marked by destruction) as in Lu 16:8. Hαιρεσις (from αιρεω) is simply a choosing, a school, a sect like that of the Sadducees (Acts 5:17), of the Pharisees (Acts 15:5), and of Christians as Paul admitted (Acts 24:5). These "tenets" (Galatians 5:20) led to destruction.

Denying (αρνουμενο). Present middle participle of αρνεομα. This the Gnostics did, the very thing that Peter did, alas (Matthew 26:70) even after Christ's words (Matthew 10:33).

Even the Master (κα τον δεσποτην). Old word for absolute master, here of Christ as in Jude 1:4, and also of God (Acts 4:24). Without the evil sense in our "despot."

That bought them (τον αγορασαντα αυτους). First aorist active articular participle of αγοραζω, same idea with λυτροω in 1 Peter 1:18f. These were professing Christians, at any rate, these heretics.

Swift destruction (ταχινην απωλειαν). See 1:14 for ταχινην and note repetition of απωλειαν. This is always the tragedy of such false prophets, the fate that they bring on (επαγοντες) themselves.