Adeptus Ministorum - Orthodoxy and Heresy: Because of the diversity of opinions within the Imperial Creed, the line between orthodoxy and heresy is often blurred. Obviously, worshipping any other god than the God-Emperor is forbidden and those who overtly turn from the Imperial Creed are punished by death, as are those who deny the authority of the Adeptus Ministorum.While those who turn to the worship of forbidden gods such as the Ruinous Powers or alien overlords are the most obvious of Heretics, many other beliefs have been declared heretical throughout the ages.What does and does not count as heresy is generally determined by the high officers of the Ecclesiarchy. Massive divisions of the Adeptus Ministorum exist to monitor and study the myriad sects that exist across the Imperium. Highly ranked, free-roaming priests with equal status to a cardinal seek out and destroy the taint of heresy.These "witchfinders" often become the scourges of entire sectors. Of course, many of the Imperium's worlds are scattered and isolated, so a sect may gain prominence on a given world and flourish for many standard years before a cardinal or witchfinder arrives from off-world and decries it as heretical. What happens next will depend upon the character of the officer.Some may convene courts of assize, sitting in judgement over those accused of heresy. Others are more wont to summarily execute sect leaders and instigate a worldwide program of religious re-education to purge the taint of errant doctrine. The most extreme, such as the notorious Witchfinder Tannenburg, put entire worlds to the pyre on the merest suspicion of heresy.The accusation of heresy in the Imperium is often used as a political weapon by those wishing to gain power over others. This can occur at multiple levels. A reasoned debate between brother cardinals can be brought to an immediate end should one of the two hint at accusing the other of heresy. A diocese that has proven tardy in the raising of tithes can be brought into line by the merest hint of the word.An accusation of heresy is a blunt tool, and one that can turn upon its wielder, for those accused might have previously unknown allies or patrons, and outright war between rival factions sometimes results. There are several variant faiths within the Imperium which the Ecclesiarchy has no choice but to tolerate, even though it disagrees fundamentally with their tenets. The cults of the Adeptus Astartes are such faiths.Every Space Marine Chapter is faithful to the Emperor and its own primarch, but they do not usually revere the Emperor as a god. Rather, to them He is a man, albeit the greatest who ever lived. This breaks with the single most important tenet of the Imperial Creed, and has on many occasions proved a source of great tension and even overt hostility between the two organisations.On the whole however, the Adeptus Ministorum and the Adeptus Astartes try to maintain cordial relations, for the Space Marines are the literal genetic descendants of the Emperor through the blood of the primarchs, which flows in their own veins ten thousand Terran years after the entombment of the Master of Mankind.The Cult Mechanicus is another deviant faith with which the Ecclesiarchy is often at odds. The tech-priests of the Adeptus Mechanicus worship their own deity, who they call the Machine God. As with the Imperial Creed, many sects exist within the Cult Mechanicus, and it is commonly held by the Priesthood of Mars that the Emperor is in fact a physical manifestation of the Machine God as the long-prophesied Omnissiah, although many in the Ecclesiarchy have great difficulty accepting this.Other sects appear to outsiders to be saturated in idolatry, worshipping the very machines they are tasked with maintaining and committing a thousand other transgressions punishable by death by the laws of the Adeptus Ministorum. Despite such differences, the Ecclesiarchy has no choice but to tolerate the Cult Mechanicus, for without the tech-priests the Imperium would literally grind to a halt.No institution can do without the Adeptus Mechanicus, just as none forgo the services of the Adeptus Astra Telepathica or the Navigator Houses, regardless of how distasteful they might find their servants.