And yet another question from my readings of the Horus Heresy. Why does the Emperor forbid the spread of religion in the Imperium and why does he abolish the religions found that have been lost? It is said in Horus Rising that the Emperor knows of the Warp and the entities that live there, so is it possible that he knows of the three Chaos gods (Tzeentch, Khrone, and Nurgle -- Slannesh was not 'born' yet)? If so, doesn't his banishing and abolishing all forms of religion leave his subjects open to the depredations of the Chaos gods?

Surely, the Emperor knew that there would be incidents that would (for lack of a better term) test the faith of his subjects. Such as when Jubal is possessed by a daemon of Nurgle, and then goes on a rampage. It is clear that Keeler and Sindermann are shaken to their core, but what comfort do they have? They have the Imperial Truth, science, and their superhuman masters who lack fear. But what good is science, when it cannot adequately explain way something so terrifying and otherworldly? We know that Keeler was not strengthened by the Imperial Truth, because towards the end of Horus Rising she turns to her faith -- the Imperial Creed -- for solstice.

Also, the Emperor is said to have created the Inquisition (at least the Ordo Mallues). But what armaments could they have against the forces of Chaos, when they lacked the faith to meet the daemons in battle? The Inquisition codexs specifically make mention of the fact that faith alone is what powers some of the Inquisitional psychic powers. Also, a number of weapons that Ordos deploy are also said to be sanctified. If the Emperor forbid his warriors faith, how would these weapons have affected the demoniac?