Board Thread:Warhammer 40k General Discussion/@comment-24383134-20140221011621/@comment-93.220.38.198-20140221121228

the colchisian "old faith" that he was raised on, was a veneratiobn of chaos, lorgar merely adapted it and said that the emperor was a new god, ruling over the "old ones " if I remember correctly. though you should read the articles on him, erebus and kor phaeron for details.

the book of lorgar was written after lorgar had sent people (serrated sun chapter) into the eye of terror. where the marines had actually bonded with demons and so on and so forth... ^^ (if i am not mistaken)