I don't think a frontal assault very often deconverts anyone. From personal experience with the deconverted and from reading those who have ceased to believe, there are three ways people rise out of faith: either they have naturally inquiring minds and get there all on their own; or they are asked why they believe and left to mull over the inadequacy of the answer in peace; or they begin reading debates between the faithful and the skeptical and reach their own conclusion. If you attack head on they rationalize and entrench, leaving you with faithful attempting valiantly to defend genocide ever more faithful the further back into the corner they are pushed.
If there is a god, I want to believe that there is a god. If there is not a god, I want to believe that there is no god.