The opiate of the masses

In the marketplace of ideas, ie. in a free society, sometimes we try to persuade people out of ideas. We criticize ideas we disagree with; we question ideas we find puzzling; we excoriate ideas we find repugnant; we make fun of ideas we think are silly and we consider this kindo' behavior quite acceptable. In fact, we think it's positively good. We think this is how good ideas emerge to the surface, and bad ideas get filtered out. We might have issues with exactly how this persuasion is carried out: should it be done politely or rudely, reasonably or hysterically, do you really have to bring it up now or later etc. But the fundamental idea of convincing other people that your ideas are right and theirs are wrong is not basically controversial. Except when it comes to religion. But why should religion be any different?