Since atheists have a common belief system and they are pretty organized why they do not consider themselves as a part of a another religion which does not have a god?
Atheism is not a religion, but a world view that denies religion as a belief in the supernatural.Yet nobody knows how nature came into existence naturally. Some say that they do, but they don't have near enough evidence to show that they might be correct. What this really means is, all of nature is supernatural... at least as far as we can tell.
Since we don't know that all of nature is NOT supernatural at its core, the atheistic belief that nature is not supernatural, is part of what classifies atheism as a religion.
