"What right have you to preach to us? You who abandoned my people to the night so many long centuries past. You have no such right; it is I who shall preach to you, and teach you the error of your faith in your so-called god!"
- —Last words of Jahoh Faas, Pontifex Maximus of Psili V (executed 798.M41)
Its cathedrals tower high above the cities of Humanity. Every settlement has at least one chapel dedicated to a local saint and even the most ramshackle hab contains a small shrine at which the occupants offer daily praise for the continued beneficence and protection of their masters.
While the Adeptus Ministorum operates on a very high level indeed, gathering tithes from entire sectors, it is in fact a vast conglomeration of individual religious cults, creeds and local sects, none of which are in total doctrinal harmony with its neighbours.
Ordinarily, theological divergence is contained by the strong leadership of regional figures, and rarely escalates beyond heated debate. So long as the essentials of the overarching Imperial Creed are maintained, then a huge range of local variation is tolerated.
While the high offices of the Ecclesiarchy appear homogenous, this is little more than a veneer that disguises a sprawling mass of variation in modes of worship, social mores, doctrinal points and teachings.
Despite the inherent variation within the Ecclesiarchy, on occasion a local sect diverges sufficiently far from the core tenets of the Imperial Creed that the higher offices declare it heretical.
Such an event is comparatively rare, and is most likely to occur when a formerly cut-off world is opened up to the greater Imperium once again, perhaps having suffered Terran centuries or even millennia of isolation.
During this time, local teachings and modes of worship come to prevail over those passed down from higher authorities, and ancient, half-forgotten, pre-Imperial beliefs resurface after countless generations festering on the outskirts of society.
When such a world is welcomed back into the fold of the Imperium, the Ecclesiarchy dispatches purity purges, often headed by the zealous warrior-women of the Adepta Sororitas' Orders Militant. Those deemed to have turned their faces from the light of the Ecclesiarchy's true creed are ruthlessly suppressed, entire populations of unrepentant Heretics sometimes burning on the pyres.
The Jericho Reach, having been isolated from the Imperium for so long during its Age of Shadow, is beset by countless such heresies, and following in the wake of every crusade advance is an army of Preachers, Confessors and missionaries, backed up by the Sisters of Battle ready to purge the Heretic with bolter, flamer and meltagun.
Yet the Jericho Reach is vast and only a portion of its worlds has been brought under the iron-shod heel of Imperial rule. Dozens of worlds, each host to countless heresies are yet to be returned to the fold, and even on those planets that have been occupied by the crusade's forces, old beliefs refuse to die.
Apostate Cardinals, a general term for any one of many thousands of the religious demagogues active in the Reach, preach resistance to the crusade and the enforced conversion that follows close behind it. They whip their followers into a frenzy of hate, sometimes literally, sometimes with words of bile and sometimes with promises of a blessed afterlife for those that die in defence of their faith.
Apostate Cardinals rule over a staggering range of cults and sects. Some are warrior-brotherhoods preaching martial virtues, while others are mendicant or penitent. Many are a bizarre hybrid of pre-Imperial religions, merged in the 31st Millennium with the Imperial Creed, and then diverging throughout the Jericho Reach's Age of Shadow.
Some have all the outward appearance of a respectable arm of the Ecclesiarchy but upon closer study indulge in forms of worship abhorrent to right-minded Imperial subjects. Some worship the God-Emperor, but make all manner of wild claims about His godhead, or even deny it entirely.
Others worship a range of gods, from a small pantheon to thousands. A few believe that the Emperor long ago turned His face from the galaxy and those who claim to rule in His name are evil or deluded. Others venerate figures that may in fact have their roots in the long dead Primarchs of the Space Marine Legions, including some that worship gods that may in fact be derived from those Primarchs who turned to Chaos.
Some devote themselves to xenos gods, knowingly or not, and at least one appears to welcome the coming of Hive Fleet Dagon to the Reach as if they themselves are its long-lost children who will soon be swept up in glorious union with their creator.
The Ecclesiarchy preaches that the ultimate end of all of these heresies can only be the worship of the Ruinous Powers. It is certainly true that the Gods of Chaos are well able to plant the seeds of heresy in the souls of the followers of these outcast cults, and watch them grow into something twisted and perverted.
Warrior creeds are easily turned to the worship of Khorne, while those that seek ancient religious truths are led astray by Tzeentch. Those who preach liberty and the casting off of oppressive social laws and restrictions are rich pickings for Slaanesh, while Nurgle is all too willing to answer the prayers of those who seek deliverance from the inevitability of death.
While the followers of the Apostate Cardinals of the Jericho Reach might not yet have fallen prey to the depredation of Chaos, the Ruinous Powers ever hunger for their souls.
- Deathwatch: Mark of the Xenos (RPG), pg. 80