@Lightlyseared If you’re going to plagiarize Wikipedia, at least do it right:
“Religion is a collection of cultural systems, belief systems, and worldviews that relate humanity to spirituality and, sometimes, to moral values.”
In any case, that’s not supposed to be a definition. And that’s good because it’s not a definition. Not just any collection of cultural systems, belief systems, and worldviews (which is the part you quoted) counts as a religion—nor even any such collection that relates humanity to spirituality and moral values. A science department has a culture, a belief system, and a general worldview, and it may differ from the culture, belief system, and general worldview of a different science department. That doesn’t mean there are two new religions to take account of.
And by the way, atheism has been around for longer than two thousand years. In fact, it has probably been around for longer than any religion currently in existence.