Why is it people blindly believe in islam doesnot it have any message for peace and social harmony?

Actually the word 'islam' has the meaning of peace and harmony in it. The Arabic word 'Islam' simply means 'submission', and derives from a word meaning 'peace' which is salam and you can see that salam is a root of i 'slam.' Islam does not teach the killing and suppression of nonmuslims, if you read its book- the Quran, its main goal is to teach- A soul at rest’ (89:27), so a state of peace in the soul. There you go again, there is its main message of peace and its reference to the soul means it's a religion not a monarchy which is politics. And finally the Quran tells Muslims to obey the Judeo-Christian scripture so Muslims are also accountable to the 10 Commandments, and that includes their "Thou Shalt Not Kill" command.