Slimboyfat,
You say “everything we are and know and experience derives its existence from something else, whereas God does not derive his existence from anything else;” and also you also make an interesting reference to the etymology of the word atheist.
When we are stuck with the details, we don’t have the whole
picture. It is like answering to the question “Which came first the chicken or the egg?” Some say
chicken, and others would say egg. But both are wrong because it’s all about an
eternal mechanism—it can’t have any beginning which is the essence of the
matter. So is the case with God and we. Neither God nor anything else could have
any beginning. Eternal recycling is what we experience.
In the East, atheism is called Charvaka system which is combination of charu (delightful) + vak (words). It arose to counter the exploitation of the clergy whose authority was based on the scriptures. Hence Charvakas rejected the authority of scriptures which was delightful to the ears of the listeners/the exploited; hence atheists were called Charvakas. Here, atheism has nothing to do with the question of whether God exists or not.