2 Peter 2:1-3
2:1 But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves. 2 And many will follow their sensuality, and because of them the way of the truth will be maligned; 3 and in their greed they will exploit you with false words; their judgment from long ago is not idle, and their destruction is not asleep.
NAS
1 John 4:1
4:1 Beloved, do not believe every spirit, but test the spirits to see whether they are from God; because many false prophets have gone out into the world. NAS
Jude 3-4
3 Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith which was once for all delivered to the saints. 4 For certain persons have crept in unnoticed, those who were long beforehand marked out for this condemnation, ungodly persons who turn the grace of our God into licentiousness and deny our only Master and Lord, Jesus Christ. NAS
APOSTASY; APOSTATE
(a-pos'-ta-si), (a-pos'-tat) (he apostasia, "a standing away from"): I.e. a falling away, a withdrawal, a defection. Not found in the English Versions of the Bible, but used twice in the New Testament, in the Greek original, to express abandonment of the faith. Paul was falsely accused of teaching the Jews apostasy from Moses (Acts 21:21); he predicted the great apostasy from Christianity, foretold by Jesus (Matt 24:10-12) which would precede "the day of the Lord" (2 Thess 2:2). Apostasy, not in name but in fact, meets scathing rebuke in the Epistle of Jude, e.g. the apostasy of angels (Jude 6). Foretold, with warnings, as sure to abound in the latter days (1 Tim 4:1-3; 2 Thess 2:3; 2 Peter 3:17). Causes of: persecution (Matt 24:9-10); false teachers (Matt 24:11); temptation (Luke 8:13); worldliness (2 Tim 4:4); defective knowledge of Christ (1 John 2:19); moral lapse (Heb 6:4-6); forsaking worship and spiritual living (Heb 10:25-31); unbelief (Heb 3:12). Biblical examples: Saul (1 Sam 15:11); Amaziah (2 Chron 25:14,27); many disciples (John 6:66); Hymenaeus and Alexander (1 Tim 1:19-20); Demas (2 Tim 4:10). For further illustration see Deut 13:13; Zeph 1:4-6; Gal 5:4; 2 Peter 2:20-21.
"Forsaking Jehovah" was the characteristic and oft-recurring sin of the chosen people, especially in their contact with idolatrous nations. It constituted their supreme national peril. The tendency appeared in their earliest history, as abundantly seen in the warnings and prohibitions of the laws of Moses (Ex 20:3-4,23; Deut 6:14; 11:16). The fearful consequences of religious and moral apostasy appear in the curses pronounced against this sin, on Mount Ebal, by the representatives of six of the tribes of Israel, elected by Moses (Deut 27:13-26; 28:15-68 ). So wayward was the heart of Israel, even in the years immediately following the national emancipation, in the wilderness, that Joshua found it necessary to re-pledge the entire nation to a new fidelity to Yahweh and to their original covenant before they were permitted to enter the Promised Land (Josh 24:1-28 ). Infidelity to this covenant blighted the nation's prospects and growth during the time of the Judges (Judg 2:11-15; 10:6,10,13; 1 Sam 12:10). It was the cause of prolific and ever-increasing evil, civic and moral, from Solomon's day to the Assyrian and Babylonian captivities. Many of the kings of the divided kingdom apostatized, leading the people, as in the case of Rehoboam, into the grossest forms of idolatry and immorality (1 Kings 14:22-24; 2 Chron 12:1). Conspicuous examples of such royal apostasy are Jeroboam (1 Kings 12:28-32); Ahab (1 Kings 16:30-33); Ahaziah (1 Kings 22:51-53); Jehoram (2 Chron 21:6,10,12-15); Ahaz (2 Chron 28:1-4); Manasseh (2 Chron 33:1-9); Amen (2 Chron 33:22). See IDOLATRY. Prophecy originated as a Divine and imperative protest against this historic tendency to defection from the religion of Yahweh.
In classical Greek, apostasy signified revolt from a military commander. In the roman catholic church it denotes abandonment of religious orders; renunciation of ecclesiastical authority; defection from the faith. The persecutions of the early Christian centuries forced many to deny Christian discipleship and to signify their apostasy by offering incense to a heathen deity or blaspheming the name of Christ. The emperor Julian, who probably never vitally embraced the Christian faith, is known in history as "the Apostate," having renounced Christianity for paganism soon after his accession to the throne.
An apostate's defection from the faith may be intellectual, as in the case of Ernst Haeckel, who, because of his materialistic philosophy, publicly and formally renounced Christianity and the church; or it may be moral and spiritual, as with Judas, who for filthy lucre's sake basely betrayed his Lord. See exhaustive articles on "Apostasy" in the Jewish Encyclopedia.
DWIGHT MALLORY PRATT
(from International Standard Bible Encyclopaedia, Electronic Database Copyright (c)1996 by Biblesoft)
Apostasy had crept into the church at the time of Jude. The great apostasy will come during the end times, however apostasy has existed from the beginning of the church age, which can be found in the Gnostic gospels some of which date to the 2nd century.