A really new revelation (that is, a revelation of something genuinely and significantly new), if taken seriously, can only eventuate in the birth of a new religion from the old. Those who embrace the new revelation will have put themselves beyond the bounds of the traditional religious community, defined as it was by its canonical revelation, its charter. The acceptance of the really new revelation creates a substantially new body of soon-to-be-orthodox belief. Once enough people accepted the Book of Mormon, there had to be a Mormon Church to accommodate them and their new beliefs. Once some ministers received the revelation of the Oneness of the Godhead during an Assemblies of God spiritual retreat, a doctrine most Assemblies ministers did not much fancy, there simply had to be a new church for the new Pentecostal anti-trinitarians: The United Pentecostal Church. When Sun Myung Moon received the revelation of the Divine Principle there was no longer any question of remaining among the ranks of Korean Presbyterians and Pentecostals, and the Unification Church was born. It had to be.
Why is it that in all such cases it is only the sectarian few who will embrace the new revelation offered them, while most will remain comfortably ensconced in familiar spiritual territory? After all, wouldn't one expect even the latter to appreciate the prospect of a new revelation since they are so zealous for the old? Aren't they themselves a group of people who know the value of a revelation, since they so highly prize the old one? Actually not. What the conservatives value in their canonical scripture/creed is not the authority of revelation but the authority of tradition. A traditional revelation provides an epistemological excuse for remaining loyal to one's own religious community rather than considering another. "Oh, sure, their religion sounds reasonably nice, but ours is revealed by God!"
But isn't it a matter of importance to them that their founder did in his day challenge the established orthodoxy? Yes, but it does not lead them to venerate present or future heretics of the same kind. No, the heretical character of the founder (in other words, his transcending the bounds of the orthodoxy of religion in his day) is in retrospect considered an excuse for the founder's own opportunistic manipulation of the parent tradition and its scriptures. It was a "progressive revelation," whereby believers in the canonical revelation might extend their community's pedigree even farther into the past, co-opting the traditionalist challengers of their faith as well as safeguarding themselves against new challengers.
For Paul to cite the Old Testament in favor of new views no Jew had ever heard of was to co-opt the Jewish canon for his own polemical use, to undercut the traditionalists of his own day by using their own pedigree against them. Justin Martyr similarly quoted Jewish scripture in his debate with Trypho the Jew. He says he will quote "your own scriptures" to prove Christian doctrine, but then has second thoughts and corrects himself: "or rather, our scriptures, since they are not yours anymore." Thus Paul and Justin would make it appear that the old guard are themselves the innovators since they have gone off the track in rejecting the new revelation which the old scriptures had anticipated! "You search the scriptures, for in them you imagine you have eternal life. And yet it is they which testify of me, and you refuse to come to me to have eternal life" (John 5:39-40). In short, the pride taken in the radical character of their founder serves to protect the religion against the challenge of the prior, parent religion as well as the challenges of today's new rivals who seek to supersede their religion in precisely the same way theirs had superseded and co-opted the old. Of course, that is exactly what the guardians of the previous order were doing in their allegiance to the old canon of their day.
But it didn't work. It never works. New religions emerge from the old by the process of sectarian mitosis: growth by splitting. Christians still claim to have the true understanding of the Jewish scriptures, and thus to have superseded them, because their founder Jesus was a prophet like unto those who had written the old Jewish scriptures. But Christians just as keenly resist the polemical-evangelistic assaults of those newer religions which seek to supersede and co-opt Christianity in the same way Christianity superseded and co-opted Judaism (or tried to). Muslims, Moonies, Mormons, all claim possession of a new book of divine oracles which "fulfills" and thus supersedes the New Testament just as the New Testament was once said to fulfill and supersede the Old Testament.
We can, then, understand why the old, established revelation exerts a strong hold on most of its members, enabling them to spurn the invitation extended by a new prophet. We still need to explain why some few are willing to jump ship and go over to the new kid in town, the new revelation, the new religion. Now we can see why it is even more remarkable for anyone to be willing to do this, in view of the great security provided by allegiance to a religion with a venerable pedigree. A really new revelation, unlike a traditional authority, must stand on its own two feet, be accepted newly and freshly, without the solid believability of tradition, the status quo. It involves much more of a risk than it does to remain loyal to the taken-for-granted authority of tradition. What kind of person is willing to breathe the rarefied air he will find out there far beyond the safety of the tried-and-true?
There will always be within the old religious community an element that is already, like the prophet of the new revelation (who may even have emerged from their own ranks), dissatisfied with the old tradition anyway. Thus they are already in the market for something new to come along. The new prophet finds a welcome among the like-minded who had kept mum about their dissatisfactions until he appears to give them voice. Muhammad had apparently belonged to a group of seekers after a simple Abrahamic faith, who then became his first converts. The Buddha's first disciples were the ascetics he had once lived with in a common quest to transcend the ritualistic charades of the old Vedic system. Joseph Smith, confused, like many of his contemporaries, at the plethora of competing revivalistic churches in the Burned Over District, prays to be shown which sect to join, and the angel Moroni tells him instead to found his own sect, restoring the pristine truth of the gospel.
Other members of the established religion are not dissatisfied with it, but they will have been led by their tradition to expect a genuinely new development. Most members will no longer take such anticipations or predictions seriously, satisfied as they are with the familiar and the comfortable, but in the case of the relative few who do expect something new, the tradition has managed to work itself out of a job. It paved the way for its own suppression, at least as far as the forward-looking minority is concerned.
Jesus, for instance, gains his first adherents from the circle of John the Baptist, a Jew already preaching in anticipation of some new revelation about to dawn. The Bab, Mirza Hussein Ali, was first embraced by members of the Sheykhi sect who were already primed for the appearance of the Hidden Imam. All Shiites would have claimed to be eagerly expecting the advent of the Hidden Imam, but their violent reaction to the proclamation of the Bab showed how far they were from welcoming anything new. Sun Myung Moon, adherent of an apocalyptic Pentecostal group expecting a new Korean messiah, receives the revelation that he is to teach the Divine Principle, so as to pave the way for the new messiah, or else to become that new messiah himself.
And, again, once the new prophet establishes his own religious community, once his revelations become a new canon, it is highly unlikely that any subsequent new revelation will be accepted. After the initial formative period, the vested interests some have in preserving the new order, the new orthodoxy, will prevail and cause the whole cycle to begin again. This is why the New Prophecy of Montanus, Maximilla, and Priscilla was repudiated by the increasingly defensive hierarchy of the consolidating Catholic Church. This is why Joseph Smith, daring new prophet, felt entitled to silence the voices of even newer