btw, I looks up the definition of religion:

a : the state of a religious religion>

b (1) : the service and worship of God or the supernatural (2) : commitment or devotion to religious faith or observance

: a personal set or institutionalized system of religious attitudes, beliefs, and practices

archaic : scrupulous conformity : conscientiousness

: a cause, principle, or system of beliefs held to with ardor and faith

I believe number 4 fits Atheism and possibly number 2 as well.