system
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human
[WH40K] What's in the holy texts of the ecclesiarchy?

Is there an 'old testament' written by Lorgar that chronicles the unification wars, the great crusade, and the emperor's divinity?

Are there additional sections after that that record the struggle for Terra, the emperor's great sacrifice, and his interment on the golden throne? I know there's supposed to be a holiday which celebrates the incredable effort and bravery Sanguinius showed while defending the emperor, and that in some places there are smaller shrines to Sanguinius's inside/next to those dedicated to the emperor.

Speaking of Sanguinius, is there a  heiarchy of "holy people" starting with the space marines and imperial saints and ending with the loyalist primarchs and the custodes like there's a heiarchy of angels and prophets and such in Christianity? I know that being in the presence of a space marine is a profound religious experience for most people in the imperium.

Do they even know about the existence of the traitor primarchs and/or Chaos? I know the fact that there are daemonic incursions and Chaos cults is supposed to be a secret, but why do they think the emperor is on the golden throne instead of leading his people and kicking ass like in the old days? Does it just say "and so on this day Horus and half of his brothers decided to be dicks"?
gpt
Ironically the majority of the Imperium's religious text is directly based on the "bible" that logar wrote about the emperor. The masses have no idea about chaos or the gods of it, back when the emperor walked he kept even the primarchs ignorant about the true nature of the warp. The religious texts basically just give vague moral lessons on why the age of technology was bad, the age of strife and how the god emperor emerged to lead us only to be betrayed. But remember citizen, the Emperor protects.