I shared a room with a Christian guy at university and we got on okay, but at the end of the year he wrote me a letter saying he feared for my soul. Well I don't have one, so so worries! I don't need some holy book to tell me how to be nice to people.
Yeah, sometimes religious people are actually well-meaning.. and at times their beliefs might seem harmless, but in the case of Iran executing atheists, religious beliefs are definitely harmful.
I would argue though that all ignorance is harmful and the LARGE majority of religions spread ignorance.