The Greek word apostasia indicates a “falling away” from the truth, especially true religion (see 2 Thes. 2:1-3). That having been said, it seems perhaps more accurate to say that true apostasy is more of a “turning away” or “turning against” than a mere passive departure through neglect. “Perhaps even more accurately, apostasy could be described as a particular group turning its back on God or rejecting the covenant relationship offered through His household (2 Chronicles 29:6; Jeremiah 2:27). Accordingly, apostasy is not necessarily a desertion from religion itself but rather a perversion of, or a rebellion against, true religion. Thus, apostasy does not require total departure from one’s faith but rather a rejection of God’s laws and His prophets or divinely appointed leadership” (Where Have All the Prophets Gone? p. 19).

“Biblical and historical evidence suggest that general apostasy is not necessary for God to introduce a new dispensation, although it sometimes happens that way. Just as apostasy can be seen as a deviation from the true course, so can a dispensation be seen as a course correction. Put another way, sometime divine reordering is necessary to correct both the orientation and the operation of the household of God” (Prophets, p. 19).

With the reordering of God’s affairs and the calling of a new founding prophet to head a new dispensation, four significant problems are overcome: (1) a living prophet is reestablished as the spokesman for God on earth, through whom our Father speaks to His children; (2) God’s divine authority that enables man to act in God’s name and lead His people is reestablished; (3) distorted doctrines are clarified and restored to their simple and pure state; and (4) the authority to perform sacraments, or rites and ordinances, is restored, along with the true nature of their purpose.

Sources:

Where Have All the Prophets Gone? Scott M. Petersen

Of course false prophets exist. They have existed in past generations and they exist today. Justin Martyr, writing only a couple of generations after the Resurrection of Jesus Christ, declared:

And just as there were false prophets contemporaneous with your holy prophets, so are there now many false teachers amongst us, of whom our Lord forewarned us to beware; so that in no respect are we deficient, since we know that He foreknew all that would happen to us after His resurrection from the dead and ascension to heaven. For He said we would be put to death, and hated for His name’s sake; and that many false prophets and false Christs would appear in His name, and deceive many: and so has it come about. For many have taught godless, blasphemous, and unholy doctrines, forging them in His name (in AnteNicene Fathers, 1:240).

The Old Testament alludes to an apostasy from truth prior to Christ’s second coming. The New Testament furnishes significant evidence both predicting an apostasy and confirming that it had already begun while the Apostles were still alive, teaching the gospel that they had been taught by the Master Himself.

Many in the Church were rejecting Jesus’ teachings for portions of the old Jewish law, selected pagan practices, and various Greek philosophies. This apostasy was brought about by fading priesthood authority followed by false doctrinal innovations. Thus, the authority to perform the rites and sacraments disappeared.

Clearly the prophecies recorded in scripture were reliable: a general apostasy from Jesus’ gospel had left behind only a dead form of a church without the living Spirit of truth.

Sources

Where Have All the Prophets Gone? Scott R. Petersen