Atheism: Atheism is a disbelief in the idea of God, or any form of deities. The term atheism originated in 16th century France, although its popularity grew only with the rise of science and religious tolerance. There are different forms of atheism, from a lack of theism to a strong agenda against theism. I disagree with the latter because although there is no scientific proof that God exists, there is also no 100% certain proof that God does not exist, and so it is a stalemate and neither side should try to convince the other. Therefore everybody is wrong until they are proven right, which would be never.
http://en.wikipedia.org/wiki/Atheism