Warren's Dark Heresy Game
Belief and Heresy
-Spreading the belief that the Imperium should not rule your planet, or the stars in general, is rebellion.
-Creating or being either a sentient machine, a biologically modified human, or returning the dead to life is tech-heresy.
-Inventing ANY new technology is tech-heresy.
-Worshiping any other being besides the Emperor and his Saints is heresy.
-Using any psychic ability without first being sanctioned by the Black Ships, or consorting with Warp creatures, is witchcraft.
-Consorting or allying with any sentient xenos race is treason.
Rebellion will bring the wrath of the Imperial Guard, Tech Heresy the Tech-Priests and Heresy, Witchcraft or Treason brings the Inquisition.
Within that framework, belief and religion throughout the Imperium is extremely varied. Cults and sects are extremely numerous, especially in Calixis Sector