He used the initiates as a literary device to give an illustration to several morals, behaviors, social adaptations, and believe systems he disapproves of.
Based on the negative comment he makes in regards to the initiates, it's not hard to tell that he doesn't have too high an opinion of organized religion.
It's also quite clear that he doesn't oppose spiritual views per say, as long as they're tempered with a healthy dosage of agnosticism, and are defined by the person themselves, instead of by religious leaders.
Early in the books (3? 4?), when Tarl learns the truth about the Priest-Kings, he initially wants to reveal this to the Goreans, but there's a discussion about how the bulk of humanity needs an artificial structure like the Initiates, that few are ready for the discipline self-determination requires.
Certainly later, in Marauders, Ivar Forkbeard shows a disdain for clergy, including their possessions, status, and their very lives. Not really a stamp of approval (though the characters and the author need not share views, of course, necessarily).
But that Norman (a pen-name suggesting his affinity with Norse-like characters like Forkbeard) created a fictional world where the gods are actually technologically advanced non-human species, and humans merely part of the food chain (and not at the top), it's unlikely he was a deist. Add to that his reliance on Nietzsche, who, while raised Christian, was harshly critical of Christianity (which may or may not equal atheism on his part), I'd say the odds favor atheist on Norman's part.
Given his outspoken libertarianism, that's another argument in favour of agnosticism or atheism on his part, I'd have thought.
On the level and looking for a square deal.