Being an atheist is not passive, it requires an active stance

[Angrboda]

I think atheism is a passive stance; critical thought, i.e. learning how to make judgments using the principles of science, and evaluate claims on the basis of sound evidence and valid reasoning --- that is the active part.

Yes, I would agree.  There is some ambiguity in the OP as to whether they mean this, or whether by active stance they mean a position characterized by political/religious activism.