This is the form of atheism that really annoys me (strong atheism). You don't know there is no god any more than any religious person (regardless of religion) knows that there is a god. The mere question is simply beyond our ontology and it is impossible to answer.
I have to disagee. Many people are very unforgiving towards atheists. Richard Dawkins writes a bit about this in his controversial book "The God Delusion". In USA, a majority of voters would not even vote for an atheist president candidate. Why is this so? In USA, one explanation may be the perceived association with communism. But I believe there may be more to it than that.
One clue is found if one ponders how many people like to call themselves agnostic rather than atheists. This is supposedly less controversial than atheism, as the atheistic world-view is seen as confronting religion head-on, saying "there is no god", while the agnostics supposedly say "i'm not sure what I think about this god-business". Thus, the explicit denial of a "god" may be what is so provocative about atheism to the general public. Maybe it's perceived as negativistic and arrogant?
To me, this is rather strange, as the distinction between atheism and agnostisism is essentially meaningless and may indicate unclear thinking about epistemology and ontology. Epistemology based on empirism should imply what coudl be called "possibilism". Inductive reasoning based on empirical observations can never rule out possible future observations. Thus, lack of positive evidence for a "god" can never disprove the possibility of future observations supporting the existance of a "god". Hence, for an empirist, there is no difference between atheism and agnostisism. No sane atheist would deny a "god" if a "god" somehow clearly manifested itself in an intersubjectively unambigous way. However, lacking such positive evidence, the question becomes why one should even discuss the existance of a "god"?
There may be one type of agnosticism that is exempt from this type of critisism. One way of interpreting Huxley's concept of agnostism that I am very fond of myself, is that theism is unintelligible and thus beyond "gnosis"*. When a theist speaks of "god", the concept is thus impossible to judge due to a lack of understanding of the concept. To me, this is an even stronger critisism of religious theism than atheism.
Anyway, to me, atheism need not be very confrontative. It is simply a statement concerning a perceived lack of positive evidence in support of theism.
Kolbjørn
*
http://en.wikipedia.org/wiki/Gnosis : "The term is used throughout Greek philosophy as a technical term of experience knowledge (see gnosiology) in contrast to theoretical knowledge which is akin to epistemology"
