Viviane:
Precisely, the claims that most theists make about their deities - and lets now use the most common sense of the word deity - is that they are ultimately immaterial in nature. That makes it impossible to acquire evidence about them. Of course, common sense tells us that it's easy to fabricate "evidence", and built a system of belief based on deception. But in any case, even if we can call BS on these religious systems, and be pretty confident that no god is going to send us to hell for it, it's still a "belief" and not "knowledge". Now most atheists get very offended when theists say that atheism is a "belief" and argue that atheism is simply a lack of belief based on the lack of evidence. But what I see here is that the lack of belief in this case is in itself a form of belief. Because what you get from lack of evidence is lack of knowledge. And those who claim lack of knowledge are agnostics, not atheists.
Eden