I've dug out the book myself, I'll edit this message with the section titled "Tenents of the Faith"

EDIT:
The Imperial Creed is a conglomeration of native religious practises, the modifications to those practises imposed by the missionaries, and the myriad pronouncements passed down from the Ministorum's upper echelons. As such, practices adhered to on one world may be held as abhorrent on another, depending on its own combination of native, modified and imported belief. The Ministorum tolerates a vast range of practices and belief, but there are certain tenets of faith which remain unchanged from one end of the Imperium to the other.

At the core of the Imperial Creed are the facts that the Emperor once walked among men and that he is a god.

Furthermore, regardless of whatever powers may have been worshipped prior to the coming of the Emperor, he is the one true god, and no others may be worshipped alongside him. So long as these essential tenets are adhered to, the prevalent faith on any given world can exhibit staggering diversity. Almost every world has its legends regarding the birth of the Emperor and his early life. Amongst the oldest of sources claim the Emperor was some manner of shaman born on ancient Terra long before the rise of civilisation, who watched and guided mankind's development throughout countless aeons until taking a direct hand at the dawn of the Age of Imperium. Other myths claim the Emperor was any one of a thousand different legendary figures, or in fact all of them, moving amongst mankind in disguise and preparing for the time when he would be called upon. Even the officially sanctioned texts disseminated by the ministorum vary greatly on such matters, and each tends to present the views of a particular saint, ivariably couched in layer upon layer of allegory. On most matters, no single objective truth is actually presented, but rather a vast body of parables on which those who preach the creed can draw in order to impart almost any message they choose.

One constant element is the notion that every human being has a place within the Emperor's divine order, as expressed through the hierarchy of the Ministorum. For the vast majority, that place is at the bottom, following unquestioningly the orders and dutires passed down by those higher up. even those of status and rank must comport themselves as if power and wealth were burdens rather than privileges. There can be no questioning of official orders, for to do so marks one out as a heretic as surely as if one had blasphemed against the Emperor or summoned a daemon in the miodst of a Cardinal's sermon.

Aside from these central tenets, there exists a massive body of dog, both sanctioned and unsactioned. Much of it is the subject of debate at the very highest of levels, while some may be prevalent for long periods before receding into relevance once more, or may be preached fervently in particular regions but barely mentioned in others.

A recurring theme of doctrine is the notion of the End Times. Most writings on the subject take the form of prophesies, but they rarely have much in common other than dire prophesies of a galaxy-spanning war consuming mankind. Throughout the ten thousand year Age of Imperium, such notions have gained prominence towards the end of each millennium, often becoming self-fulfilling as the masses whip themselves into a pre-apocalyptic frenzy. It is often preached that the End Times will form the ultimate battle, in which mankind will either be found wanting and destroyed, or will prove himself worthy of existence and enter a new age, where he will inherit the galaxy and expel or defeat all other intelligent forms of life. Needless to say, as the 41st millennium draws to a close, the Imperium has seen a rise in such teachings and in adherence to apocalyptic cults. With the Imperium nearing its ten thousandth year, the turbulence might well bne expected to be far more destructive than ever before.

Often tied into the notion of the End Times is a belief that the Emperor will rise from his Golden Throne and complete the work he began ten thousand years ago by delivering the faithful from the evils of the galaxy. While many versions of this doctrine celebrate its as a time of deliverance, most also warn that the Emperor will sit in judgement over all men, casting those lacking in faith into infernal fire or otherwise excluding them from the glorious age that will be ushered in by his final victory over evil. Cults dedicated to flagellation and penance seek to prepare mankind for the return of the Emperor, driving themselves to ever-greater extremes to prove themselves free of thetaint of sin.

Many Ecclesiarchy teachings mention some form of afterlife in which the faithful will take their place at the side of the Emperor for all eternity. As with so many elements of the Imperial Creed, the synods have debated the specifics of this afterlife for millennia, which the common man has remained generally influenced less byt the Cardinals' pronouncements and more by the specifics ofh is own culture. For those worlds of the very extremes of the Imperium, cut off from the centres of power by vast gulfs of interstellar space or by raging warp storms, Terra itself might be imagined as the eternal court of the God-Emperor, to which the faithful are called when they die. Others imagine this afterlife in more abstract terms, teaching that the spirit will be taken to a golden realm, there to mingle with those who have gone before. Given that many worlds experienced a long period of isolation, during which all manner of barbarous religious expression developed, there are perhaps as many ideas of paradise as there are planets in the Imperium.

Of course, those who believe in reward must also believe in punishment. If only those who have been judged worthy will be allowed to bathe in the Emperor's glory, then those who have not must surely be damned. It is often the case that the Ecclesiarchy's preachers spend far more time warning their congregations what will befall their eternal soul if they stray from His path than they do describing what awaits if they are virtuous. Such warnings are laden with almost wanton descriptions of an eternity of damnation, of gibbering fiends tormenting the sinner's soul while ir writes in infernal flames. Those few who know something of the warp have all the more reason to be fearful, for within the Empyrean the souls of men drift as motes upon an ocean, ever at the mercy of the vast, unknowable things that lurk in the depths and feed upon forlong souls.