Well, just a basic a idea here. If I understand correctly, in the setting there isn't much room for doubt in the existence of the gods... The term atheism technically refers only to the lack of belief in the existence of god or gods. With that in mind, I'd like to suggest that the term be changed to misotheism ( http://en.wikipedia.org/wiki/Misotheism ), which is more appropriate for the belief that while the god exists they are not worth worship, or the hatred of the gods.

Yeah, it's doesn't really matter much for the game purposes, it's just that I feel Atheism is wholly inappropriate here, and also might disseminate a wrong concept of what is atheism (I'll not enter on it right now, as it's not the purpose of the topic, but for now, suffice to say that it's does not make any statement other than the lack of belief in the existence of gods)