I make a distinction between religious belief and religion. The former I respect, ultimately, as a personal choice (that is not to say I wouldn't try to present an alternative if it was appropriate!). The latter I have little respect for :)
But that's a problem. We don't pretend to respect people for having silly beliefs, except when it is religious - why this exception? I find it helps to think of religious belief/conviction as a socially acceptable form of mental disease, comparable to examples in drug use.
I suspect you're preaching to the converted :-) I rationalise it by accepting this phenomenan exists - I will fight when it is detrimental of course, but otherwise just let it slide.
if you can make someone believe anything (e.g. there's this god with x,y,z attributes), you can make them do anything.