Starriors. When I was but a lad, these toys were produced by Tomy and hawked by Marvel Comics. The toys had some cool designs, but were shoddily made, and generally crap. But inside each one of them came a mini comic, and then Marvel put out the miniseries, written by Louise Simonson with gorgeous covers by Bill Sienkiewicz, and just like that I was hooked.
For those of you reading this who aren't familiar, the premise of Starriors was that, facing increasingly violent solar flares, Man abandons the earth, going into hibernation. They build three types of robots to look after things while they're gone. The Protectors are supposed to keep the Earth in a ready state for man's return, keeping up the buildings and such. The Destructors are supposed to ward off alien invasions (?) and the Guardians are supposed to guard the people themselves. One of the Destructors, the awesomely named Slaughter Steelgrave, realizes that if man ever wakes up, they might not be needed anymore. To make sure that never happens, he destroys all the Guardians except one, turns off mankind's alarm clock, wipes their location from the memory banks of all the other robots, and enslaves the Protectors. Time passes, and the human race becomes a myth until one of the Protectors finds a skull, proving the existence of man. The Protectors rise up as one and blah blah blah, you can see where this is going, right?
What a great setup! Belief in man as an underground cult spread by robots in an abandoned earth, varied robot designs (my favorite was Deadeye - a massive, heavily armed, blind Tyrannosaurus Rex robot who was led around by Cricket, his robot pterodactyl scout), but best of all, a neat little detail - each had a control circuit, essentially their brain, that was fashioned in the shape of a man reclining on a chair inside their heads, under a transparent piece of plastic. Until I got the miniseries which explained what they really were, I had come up with my own story that I still like better. I figured that the human race had ensconced itself in these giant robots, their bodies in hibernation, their minds controlling the robots. They were in there so long, though, they forgot they were human at all. The idea of these robots wandering around the wastelands, searching for man to save them while he is within them the whole time appealed to me, and still does.
So I'm using that idea. In From the Ashes, Prophets are pre-apocalypse humans, strapped into robot exoskeletons that have forgotten they are human at all. Wandering the wastes, preaching a messaianic, Millenarian faith which promises the return of "True Man", who have been slumbering all this time. Soon, they preach, soon True Man will return to bring the world back to it's former glory! Their timers were set for 1,000 years, and that time fast approaches!
Or at least that's what they say, and they've been saying it for a couple hundred years (they haven't been wrong, mind you, but rather have an evolving understanding of the truth). It is their duty to seek out these bastions of True Man and guard them from the False Men (ie anyone alive today - even non-mutated humans have been corrupted by this fallen earth). They do accept converts to their religion from the False Men, but they must prove their devotion by fasting and self flagellation, to purge the contaminants of this earth from their bodies.