Sam Harris, says in his book The End of Faith that faith and religion are “the most prolific source of violence in our history.” The three-volume Encyclopedia of Wars, which chronicles some 1,763 wars that have been waged over the course of human history, begs to differ.
For those wars, the authors note the causes of each. Consider this; they categorize 123 as being religious in nature, which is an astonishingly low 6.98% of all wars. However, more than half of them, 66, were fought in the name of Islam. Take those out, and the percentage of non-Islamic religious wars is a mere 3.23%.
So the next time someone tries to use the Crusades as a way to paint religion as the primary source of all war, just ask them, “Is that the best you can do?” Takes quite a bit faith to believe that.