@Drnaline,
Captain America for the win
it's in our nature to destroy each other, but by the numbers I would say the crusades puts religion WAY over the top. And just look in the last few years.
911 (religous war by radical Islam)
Afghanistan (Our secular forces were opposed on the principal of a god)
The war on terror (more of the same)
infact if you color mapped the globe based on violent death since the inception of civilization, Isreal would be the deepest red. And 99% of the deaths there have a religious undertone