The very concept of 'faith', common to all religions, requires unquestioning belief and this runs counter to the principles of objective investigation and therefore counter to what is necessary to 'dispell ignorance'.
I think that is a mistaken assumption on both sides of the aisle. I imagine that you've seen it here quite often.
But there is nothing in religion that requires unquestioned belief. In fact, a belief that is unquestioned, unchallenged, untested or tempered is a pretty weak belief. This is one reason so many people seem to get upset when their beliefs are challenged.
I agree that many time religious beliefs are taught and religious leaders use the tactic of "Unquestion" as an easy cop-out. But that's all it is. Accepting Dogma, whether it's religious, political, cultural or philosophical is easy. Critically examining those beliefs, testing and tempering them is work, hard, often unpleasant, work.
Aslan is not a Tame Lion