Verse 1: But (Deut. 13:1) there were false prophets also among the people, even as (Matt. 24:11; Acts 20:30; 1 Cor. 11:19; 1 Tim. 4:1; 2 Tim. 3:1, 5; 1 John 4:1; Jude 18) there shall be false teachers among you, who privily shall bring in damnable heresies, even (Jude 4) denying the Lord (1 Cor. 6:20; Gal. 3:13; Eph. 1:7; Heb. 10:29; 1 Pet. 1:18; Rev. 5:9) that bought them, (Phil. 3:19) and bring upon themselves swift destruction.
[But there were also False Prophets] It coheres well with what precedes. For not all are Prophets of God who say that they are such. Many falsely take to themselves that title. Many are stirred by a Devilish Spirit (Grotius). Καὶ/ also here has regard to the preceding; that is to say, With those Prophets sent by God also arose False Prophets, who, says he, were not sent, but were, or arose. He had commended the reading of the Sacred Scripture; here he shows the use of it, namely, lest they be seduced, etc. (Gerhard). From the mention of the Prophets he opportunely transitions to the principal argument of this Epistle, which concerns the avoidance of False Prophets, whose pursuits and character he describes in general (Estius).
But there were false prophets also: the apostle having been exhorting them to continuance and progress in faith, admonishes them here of such as might labour to draw them from it; and having made mention of the Old Testament prophets, holy men of God, he hereby takes occasion to tell them of, and caution them against, false teachers which would be among themselves. This also in the text plainly relates to what went before: q.d. Together with those prophets which were sent by God, there were likewise false prophets, such as were not sent of him.
[Among, etc., ἐν τῷ λαῷ] Among the people (Beza, Piscator), κατ᾽ ἐξοχὴν, par excellence, namely, of God (Gomar, thus Piscator, Gerhard), or Israelite (Grotius, Gomar, thus Estius, Gerhard), as the article indicates (Piscator, Gerhard). See 1 Kings 22:6; Jeremiah 28; Ezekiel 13:2; 22:25, 28; Zephaniah 3:4 (Grotius).
Among the people; the people of Israel.
[Even as (or, similarly also [Gerhard]) in you (or, among you [Beza, Piscator, Gerhard], according to a Hebraism: Nevertheless, thus also Cicero, Friendship, says he, is only in the good, that is, among the good [Gerhard]: Among you, namely, Christians [Estius, Gerhard], in the New Testament [Gerhard], as they were among the ancient people [Estius]) shall be lying teachers, ὡς καὶ ἐν ὑμῖν ἔσονται ψευδοδιδάσκαλοι] Teachers false (Beza, Piscator), or, lying (Drusius), that is, inventors of lies (Gerhard). He principally understand Carpocrates and his associates, who were in the times of Hadrian (Grotius); the Gnostics (Hammond, certain interpreters in Gerhard), who arose either at that time, or immediately after that (certain interpreters in Gerhard); or, Simon Magus with his disciples, even Cerinthus, and the Nicolaitans (Estius), of whom mention is made in Revelation 2:5 (Gerhard). Paul also, and Jude, made mention of such prowling about in their time. Whence in what follows concerning them he often speaks in the present tense. But he says there shall be, because those were few in comparison with those who yet were going to arise (Estius). Here, the future verbs indicate that here all heretics of all times are treated (Gerhard).
Even as there shall be false teachers; teachers of false doctrine, Matthew 7:15; Acts 20:29. Among you; among you Jewish, as well as among the Gentile Christians; or, among you as Christians and God’s people under the New Testament, in opposition to the people of God under the Old.
[Who, etc., οἵτινες παρεισάξουσιν αἱρέσεις ἀπωλείας] Who shall introduce (or, shall bring in covertly [Erasmus, Illyricus], shall introduce secretly [Grotius], stealthily and slyly [Gerhard], under the appearance of piety creeping into the flock [Beza, similarly Gerhard]; or, beside Christian doctrine [Gerhard, similarly Beza], which they shall not deny, but shall corrupt [Gerhard]; by adding, or subtracting, or changing [Beza], which the preposition παρὰ indicates [Piscator, Gerhard, Beza]: Or, beyond notice, or with no one observing; that is to say, παρὰ παρατήρησιν εἰσέρχοντες, coming in beyond observation [Gerhard]: Hence παρείσακτοι, men secretly brought in, Galatians 2:4 [Estius, Gerhard]: Hence παρεισέδυσαν, they crept in unawares, Jude 4 [Gerhard]) heresies (or, sects [Grotius, Camerarius, Vulgate]: For the word αἱρέσεως is neutral with its own nature [Grotius, thus Estius]; but it is distinguished by an addition [Grotius], and by the use of the Church is now received in a negative sense [Estius]: Now, heresy is false doctrine concerning the foundation of religion, with contumacy toward the confutation of the Church, and repeated admonitions, Titus 3:10 [Gomar]) destructive (Beza, Piscator, etc.), or, pernicious (Vorstius, Grotius), or, of perdition (Vulgate), of destruction (Piscator). Ruined (Gerhard, Vatablus), and bringing ruin (Estius, Gerhard), on account of the shipwreck of the faith. It is a Genitive denoting effect, added either for the sake of restriction, because αἵρεσις is a neutral word (Estius), or rather, for the sake of description (Estius).
Who shall privily bring in: the Greek word signifies either to bring in slily and craftily, under specious pretences, and without being observed, Galatians 2:4; Jude 4; or, to bring in over and above, or beside the doctrine of the gospel, which they did not renounce; or both may be implied. Damnable heresies; Greek, heresies of destruction, i.e. destructive, such as lead to destruction, viz. eternal, or damnation.
[Even, etc., καὶ τὸν ἀγοράσαντα αὐτοὺς δεσπότην ἀρνούμενοι] Even denying the Lord that bought (or, acquired [Vulgate]) them (Erasmus, Pagnine, Beza, Piscator, etc.). By δεσπότην/Lord here they understand, either, 1. Jesus Christ (Estius, Menochius, Drusius, Piscator, Grotius), who is commonly called Κύριος/Lord in the New Testament (Vorstius); but also δεσπότης/Lord sometimes, as in Acts 4:24; Revelation 6:10; who also redeemed them, inasmuch as He died for all (Grotius, thus Gerhard); even for reprobates, who were made partakers of that redemption according to some effects (Estius). [But] such words do not always signify the Effect, especially the final Effect, but often Efficacy. Thus σώζειν, to save, is taken in 2 Timothy 1:9 (Grotius). Others: He calls those bought by the blood of Christ κατὰ δόξαν, with respect to external appearance, because to others they appeared to be truly faithful (Piscator). Now, they were denying this Jesus, [either, 1. directly and expressly] because they were withdrawing their honor from Him, saying that He was born of His father Joseph, and that many of the flock of Carpocrates are equal to Him, some are even superior, Irenæus’ Against Heresies 1:24 (Grotius); or, denying that Christ is God, like the Arians (Menochius): [or, 2.] if not in word, certainly in deeds, and in depravity of doctrine (Estius, thus Gerhard), or in those things which follow upon their doctrine (Gerhard). Or, 2. God the Father (Gomar, Lightfoot’s Harmony, Chronicle, and Order of the New Testament 51, Vorstius), who without controversy is called δεσπότης/Lord, Luke 2:29; Acts 4:24; 2 Timothy 2:21, moreover, (as I think) Jude 4 and Revelation 6:10 [concerning which see Gomar]. The Son is never so called. To buy here is the same thing as to acquire, and to make His own, as in Isaiah 55:1; Revelation 3:18 (Gomar). This is taken out of Deuteronomy 32:6, Is He not thy Father that hath bought thee? namely, from Egypt, so that He might make thee a people peculiar to Himself (Lightfoot’s Harmony, Chronicle, and Order of the New Testament 51). God the Father everywhere is said to have redeemed us, just as also Christ. Consult Acts 20:28; 1 Corinthians 6:20; Ephesians 5:25; Revelation 1:5 (Vorstius).
Even denying; either in their words or their practices, either directly, or by consequence of their doctrines or actions; they that profess they know God, but contradict that profession in their lives, are said to deny him, Titus 1:16. The Lord; either, 1. God the Father, so called, Luke 2:29; Acts 4:24, etc., and probably Revelation 6:10; nor is there any necessity, but, Jude 4, the word may be understood of God the Father. Or rather, 2. Christ. That bought them: if we understand it of God the Father, the sense is, either, 1. Denying God that bought them, or acquired them and made them his, viz. by calling them out of the darkness and gross wickedness of the world, to the knowledge of Christ and the gospel, and the fellowship of his church. In this general sense the word buying is sometimes taken, Isaiah 55:1; Revelation 3:18. Or, 2. Denying God that bought the people of Israel (whereof these false teachers that should be among the Christian Jews were to be a part) out of Egypt, to make them his peculiar people, whereof they would boast themselves, and yet by their wicked practices deny that God that bought them; the words seem to be taken out of Deuteronomy 32:6: Is not he thy Father that hath bought thee? as likewise from verse 5 of that chapter. Peter calls them spots, verse 13 of this chapter. But if we understand it of Christ, which seems most probable, the sense is, either, 1. That Christ bought or redeemed them, (in which sense the word is sometimes taken,) in that by his death he purchased the continuance of their lives, and the staying of their execution, and rescued them from that present destruction which, without Christ’s interposition, had seized on them, as it had likewise on the whole visible creation immediately upon the apostacy of mankind. Or, 2. This is spoken not only of their pretences, that they should profess themselves redeemed by Christ, but in the style of the visible church, which should judge them to be so till they declared the contrary by their wicked actions; and it likewise holds true in a forensical or judicial style, according to which whosoever professeth himself to be redeemed by Christ, and yet denies him in his deeds, is said to deny the Lord that bought him; it being alike as to the greatness of the crime, whether he be really redeemed, or, professing himself to be so, denies his Redeemer.
[Bringing instead, etc., ἐπάγοντες ἑαυτοῖς ταχινὴν ἀπώλειαν] Fetching (or, bringing upon [Piscator]) themselves swift (that is, unexpected: for that which is such appears to happen swiftly and suddenly [Estius]) destruction (Piscator, similarly Beza, Gerhard). By the war of Bar Kokhba, to whom they adhered, as worldly men (Grotius). Swift, that is, more quickly than their expectation, since they were promising themselves life, long in this life, and eternal in heaven (Gerhard); that is to say, they shall perish forever (Gerhard, similarly Estius).
And bring upon themselves swift destruction; shall hasten their own destruction, it may be temporal in this world; to be sure, eternal in the other. It may be called swift, as coming upon them unawares, and when they think least of it, as 1 Thessalonians 5:3.
 Greek: ἐγένοντο δὲ καὶ ψευδοπροφῆται.
 De Amicitia 18.
 Carpocrates of Alexandria was the founder of a libertine Gnostic sect in the early second century.
 Hadrian was Roman Emperor from 117 to 138.
 Cerinthus (c. 100) was a heretic: He taught his followers to keep the Jewish law for salvation, and denied the divinity of Jesus (believing that the Christ came to Him at His baptism); like some Gnostics, he denied that the Supreme God made the world, and believed that the bodyless, spiritual Christ inhabited the man Jesus. He also anticipated a millennium of earthly pleasures after the Second Coming but before the general resurrection.
 Although the Nicolaitans are mentioned by the early Church Fathers, little is known with certainty about them beyond what is mentioned in John’s Apocalypse, that they ate things sacrificed to idols, and committed fornication. See Revelation 2:6, 14, 15.
 For example, 2 Thessalonians 2:7; Titus 1:10.
 Παρεισάγω is a compound of παρὰ and εἰσάγω, to bring in.
 From παρεισάγω.
 Galatians 2:4: “And that because of false brethren unawares brought in (παρεισάκτους), who came in privily (παρεισῆλθον) to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage…”
 1 Timothy 1:19.
 Acts 4:24: “And when they heard that, they lifted up their voice to God with one accord, and said, Lord (Δέσποτα), thou art God, which hast made heaven, and earth, and the sea, and all that in them is…”
 Revelation 6:10: “And they cried with a loud voice, saying, How long, O Lord (ὁ δεσπότης), holy and true, dost thou not judge and avenge our blood on them that dwell on the earth?”
 Arius (c. 250-336) was a presbyter in Alexandria, Egypt. He became embroiled in controversy when he asserted that the Son of God was a subordinate being, created by the Father. His teaching was condemned at Nicea in 325, but the heresy has endured.
 Luke 2:29: “Lord (δέσποτα), now lettest thou thy servant depart in peace, according to thy word…”
 2 Timothy 2:21: “If a man therefore purge himself from these, he shall be a vessel unto honour, sanctified, and useful to the master (τῷ δεσπότῃ), and prepared unto every good work.”
 Jude 4: “For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ (τὸν μόνον δεσπότην Θεόν, καὶ Κύριον ἡμῶν Ἰησοῦν Χριστὸν).”