PROS AND CONS
There are many arguments and counter-arguments when discussing the topic of religion causing war. Many critics argue that throughout history, religion has been the single greatest source of human-caused wars, suffering, and misery. In the name of God (by whatever name), more suffering has been inflicted than by any other man-made cause. (Pro Side) Critics on the other side counter that modern secular ideological movements are actually responsible for much greater and more indiscriminate violence than any religion ever has been. (Con Side)
They further contend that the claim that religion causes war is not supported by the historical or contemporary evidence. They maintain that only 7 (10%) of all the wars (and the same percentage of 20th century wars) had clear religious motivation, and most had no detectable religious motivation at all. The counter argument is that flies in the face of historical fact: for every year of peace in humankind's history there have been fourteen years of war, 90% of which have been fought either because of, or under the banner of, God (by whatever name).
Both sides make very compelling arguments and valid points backed up by facts and statistical data - so who's right? Does religion cause war? One could easily fall on either side of the coin on this complex issue and still be on the side of sound reason, intellect and truth. However, a close and unbiased examination of past wars lead to one conclusion over the other: religion does cause war.
RELIGIOUS WARS KNOWN AND UNKNOWN
One of the major examples where religion caused war would be the Crusades. The Crusades, fought in the 11th century, were a series of "Holy Wars" between Christian and Muslims that was centered around the city of Jerusalem. In summary, the Turks took Jerusalem in 1065 and massacred 3,000 Christians. This started a chain of events which lead to the start of the Crusades.
Opponents of the claim that religion causes