That said, Atheism doesn't even qualify as a worldview, as none of the things you mentioned are actually valid qualifications for each criterion. The difference between the qualifiers used for religions (rituals, beliefs, narratives, ethics, etc.) are part of the religion by definition. The ethics outlined in the bible are the official "Christian" ethics, the rituals and narratives are all essential parts of Christianity. Alternatively, Atheism is simply the lack of belief in a God. Anything else beyond that can be described as "Atheistic" in the sense that they don't involve God, but they are not purely Atheist things to do and are not essential parts of Atheism. If you are Atheist you do not have to believe the theory of evolution is true, and not all Atheists do. You do not have to reject God to be an Atheist. That assumes you believe in God in the first place. A person raised as a hermit in the woods would never have the experience of "rejecting God". So you could believe evolution is false, never "reject God", not go to Atheist gatherings (or even know that they occur), never know about any prominent Atheists, never spend time considering the ultimate nature of reality or convincing yourself of the non-existence of God or that faith is illegitimate, never get married, not be concerned about the religion vs. secular nature of your funeral, and not believe that nature is sacred, and you can still be an Atheist. The only thing involved in Atheism is not believing religious claims of a God. Yes you can argue that some things are Atheistic, but that ultimately just means they don't involve God, not that they are a "part of Atheism" or what have you. In essence, you don't have to do anything to be an Atheist. There are no positive beliefs, rituals, or experiences that are a central part of Atheism. If you are not religious, you are Atheist by default.
—Glenwing