Since it’s logically impossible to prove a negative, atheism can only go so far. However, religions make extraordinary claims, which should require extraordinary evidence, the lack of which is papered over with faith. I suppose atheists have a similar faith of the opposite nature, but does faith in something make it a religion?
Well, within reason it’s logically impossible to state anything about the existence of God. So yes, atheism is a faith, and they do have their own churches, ironically becoming the thing that they eschewed.