Atheism as opposed to agnosticism is a statement of certainty. True belief in an unproven assertion is an act of faith. I will leave it to the reader to decide if this specific act of faith constitutes a religion.
Atheism and agnostic are not mutually exclusive...
Gnosis has to do with certainty, atheism is a belief (rather, rejection of your beliefs), not a certainty
You can be an Agnostic Atheist or a Gnostic Atheist
Atheists are not required to know for certain that zero gods exist... That is ignorant, uninformed, and makes you look foolish claiming that you know Atheists better than an actual Atheist does
How about you define your religion, and let Atheist define our non-religion in a way that makes sense to those of us who aren't delusional?
Thanks