Lets be clear, in both the Bible/Torah and the Qur'an God/Allah ordersd killings, the difference is, in the Bible, God targets only specific people, eg Caananites and Hittites, whereas in the Qur'an, eg Sura47:4-7 says 'When you meet unbelievers, smite their necks., then when you have made wide slaughter among them tie fast the bonds'.
This means everyone who is nor a Muslim.
So while religion is not responsible for a lot of the carnage, it surely is for a hell of a lot more.
Anyway, I personally believe that people can only live in harmony for a short time, then 'Freedom of Will', a gift from God, becomes apparent, and we start killing each other.