I do know that the nine Primarchs who remained loyal to the Emperor are venerated as saints.  To the best of my knowledge, Roboute Guilliman is widely known and respected for restoring some amount of stability to the Imperium in the aftermath of the Horus Heresy. 

 I do know that the nine Primarchs who remained loyal to the Emperor are venerated as saints.  To the best of my knowledge, Roboute Guilliman is widely known and respected for restoring some amount of stability to the Imperium in the aftermath of the Horus Heresy. 

you might see the Imperial creed as a great puzzle of faith put together and tie with the name of the Emperor.

Each world or cluster of world have a distinctive way to interpret the creed and each of them have their own saint and martyr.

Then, you also have more global personnification like the Primarchs of course but as are some of the mightioest general of the Imperium like Macharius, or Angevin and so many more.

Then you have the saints of the church who are many with local figure venrated.

But you also have primitive world who worship the sun or a volcano, or who knows what, those element had been merge with the global creed and are becoming avatar of a well known figure.

Faith and creed are many and quite evrything can be found in it..

mrady said:

The AM worship the Machine god in the personnification of the Omissia. This figure is commonly held (by the AM) to be the Emperor himself when he first visited Mars before the great Crusade. There is also some (Heretical) evidence that they could also be referring to the C'tan Shard of the Deceiver found on Mars Just prior to the Awakening of the Necron Empire.

ranoncles said:

On the contrary, much the same is said of Catholicism from those without. As a Catholic, I venerate and revere the saints, and ask for their intercession, but there is a distinct difference from praying to a saint, and asking for their intercession. Praying to a saint is saying that they are the same as God and hear prayers and respond to them; which should not be done, but asking for their intercession is the same as saying, "Please pray to God for me and with me, so that my prayers are taken to God."