Well, the way i see it, i would not look down on christians, muslims, jews, hindus, scientologists, spaghettimonster-ists (can't rememebr the name) or whatever because they're different than me, but if they take their relegion to an extend that i find stupid i do consider them stupid.
I don't see relegion as an excuse to to stupid stuff, i don't care if people have what i would consider silly rituals or other stuff like that, i prolly do lots of stuff they find solly as well.
But if someone uses relegion as a way to scam people off their money (liek scientology) i see them as con artists, not cause of their relegion, cause it's just a tool, but because of the scams they pull.
If people kill others in teh name of their relegious figures, i don't look down on them as murderers due to their relegion, but due to their murdering. the relegion was just a "convenient excuse".
If people beat of homosexuals due to their relegious beliefs, i don't blame them for their relegion, but for their homophobic biggotry, and violent acts, the relegion was again just a "convenient excuse".
Summed up, you shouldn't look down at people due to their relegion, but you shouldn't think bad stuff they do is okay, just because it's part of their relegion either, their relegion isn't a shield that can cover their bad/evil acts.
Hope it makes sense.