Christians: how do you justify a religion that, from its very beginning spawned the crusades?

from the day the book was written, it powered the single largest mass murder in the history of mankind. followers were told staight up that to kill an infadel was not murder, but a path to heaven. sound familiar? the bible teaches us to love our neighbors but says that people that have different beliefs or life choices will go to a place of eternal hell? dont get me wrong, I LOVE GOD, who is the universe and the deeper cosmic identity of myself and all existence, but the bible too obviously teaches intolerance and promotes negative energy towards so called sinners, who many times, are doing no harm to anyone, let alone their own souls. my question is, why promote intolerance? god is EVERYTHING, and LOVE is his vibration always