Atheists do not hold one set of beliefs concerning the cause, nature and purpose of the universe any more than theists hold one set of beliefs about them. There is definitely no single moral code governing the conduct of human affairs that all atheists adhere to.
Atheists, by definition, do not consider the universe to be the creation of a superhuman agency or agencies.
Most atheists do not participate in devotional ritual observances.
Is this the definition you think makes atheism a religion? If so, why?
There is no specific fundamental set of beliefs and practices generally agreed upon by atheists, unless you're claiming that the belief in the non-existence of God makes a "set". I suppose that technically, a set can have one member (though a set can also have zero members, so I think it'd be just as logical to argue that the entire planet is a single religion, since they agree to an
empty set of beliefs
), but I think this is stepping beyond the use of the term in normal speech.
Is this the definition you think makes atheism a religion? If so, why?
This one's clear enough: atheism does not meet this definition of religion. There are atheist associations, but most atheists do not adhere to them.
Is this the definition you think makes atheism a religion? If so, why?
Fast and loose with words? Mr. Pot, meet Mr. Kettle.
Atheism is no more a religion than theism is one.
There are atheistic religions (certain forms of Buddhism come to mind, and some other religions allow the individual member to decide for themselves whether God exists) and there are theistic religions (i.e. most of them
). There are theists who don't belong to any religion (I'd argue that a good portion of the people who describe themselves as "spiritual, not religious" fall into this category) and there are atheists who don't belong to any religion as well (i.e. most of them
).
But the flipside to arguing, as you effectively are, that the status of a set of peoples' belief in God is enough to define them as a religion is that
theism as a whole is a religion as well. I don't know any reasonable person who would agree that Christianity, Islam, Wicca, Zoroastrianism, Native American religion, cargo cults, theistic Buddhism, Hinduism, worship of the Greek pantheon, etc., etc. are all the same religion. This is the implication of what you're arguing; unless you're okay with this, I think you should reconsider your position.
There are theistic religions. There are religions with theist members. This does not make theism a religion. By the same token, there are atheistic religions and there are religions with atheist members, but this does not make atheism a religion.