...despite the best arguments-- the many points of which can be categorically swept aside, ridiculed, and/or ignored-- the truly devout will unlikely be swayed;
there's little in the way of support in terms of outside sources and the like but, rather, often the support comes in the form of circular reasonings;
there's often a glaring lack of knowledge of or insight into the very ideals that one is putting forth;
there's irrationalism and/or emotionalism involved-- often to the level of physical violence and death and threats thereof (burnings-at-the-stake, etc.);
the devout can have great persistence-- even coming to your door at suppertime;
and they can build great cathedrals.