If you want him to be to cynical to have faith in a god, make him an ur-priest, stealing mana from gods for his own use and using sacrificial victims to gain power from fiendish patrons...
Do tell... This sounds evil and possibly down his path. Is there some set of rules somewhere about things like this that I might read? Any links or names would be nice. Also, what is a ur-priest? Or is that also part of it?