Tell that to Gann of Dreams he pretty much outright denies the existence of deities but than you have the other side that thinks it is a waste of time to worship any deity Warlocks most often think this way because they deal with outsiders why worship them when you can make a deal with them?
Just a cursory search on Google (since it's been forever since I touched NWN2) tells me Gann doesn't respect or worship gods because they are not worthy of it, which makes him Faithless. As I said, in Faerun, gods are very real. To deny that would make you delusional in that world. The setting does not allow any other reasoning.
