"There are many common misconceptions about religion that are often taken as unquestioned facts, such as the idea that religious people are inherently anti-science, that a literal reading of holy texts is the "true" religious stance, that faith is incompatible with reason, and that all religions claim to posses sole and absolute truth.
While all these ideas are true for a minority of the population, they do not describe normative religious beliefs and practices for the majority of believers. It is understandable that these misconceptions persist, though, because they come from the loudest voices on the extremes, and like other polarizing positions in politics and culture are simplistic ideas that promote easy "us vs. them" thinking. But there is one common misconception about religion that is voiced often and consistently as an obvious truth — often by educated, thoughtful people –that is just not factually true: The idea that religion has been the cause of most wars.
In his hilarious analysis of The 10 Commandments, George Carlin said to loud applause, "More people have been killed in the name of God than for any other reason," and many take this idea as an historical fact. When I hear someone state that religion has caused most wars, though, I will often and ask the person to name these wars. The response is typically, "Come on! The Crusades, The Inquisition, Northern Ireland, the Middle East, 9/11. Need I name more?"
Well, yes, we do need to name more, because while clearly there were wars that had religion as the prime cause, an objective look at history reveals that those killed in the name of religion have, in fact, been a tiny fraction in the bloody history of human conflict. In their recently published book, "Encyclopedia of Wars," authors Charles Phillips and Alan Axelrod document the history of recorded warfare, and from their list of 1763 wars only 123 have been classified to involve a religious cause, accounting for less than 7 percent of all wars and less than 2 percent of all people killed in warfare. While, for example, it is estimated that approximately one to three million people were tragically killed in the Crusades, and perhaps 3,000 in the Inquisition, nearly 35 million soldiers and civilians died in the senseless, and secular, slaughter of World War 1 alone.
History simply does not support the hypothesis that religion is the major cause of conflict. The wars of the ancient world were rarely, if ever, based on religion. These wars were for territorial conquest, to control borders, secure trade routes, or respond to an internal challenge to political authority. In fact, the ancient conquerors, whether Egyptian, Babylonian, Persian, Greek, or Roman, openly welcomed the religious beliefs of those they conquered, and often added the new gods to their own pantheon.
Medieval and Renaissance wars were also typically about control and wealth as city-states vied for power, often with the support, but rarely instigation, of the Church. And the Mongol Asian rampage, which is thought to have killed nearly 30 million people, had no religious component whatsoever.
Most modern wars, including the Napoleonic Campaign, the American Revolution, the French Revolution, the American Civil War, World War I, the Russia Revolution, World War II, and the conflicts in Korea and Vietnam, were not religious in nature or cause. While religious groups have been specifically targeted (most notably in World War II), to claim that religion was the cause is to blame the victim and to misunderstand the perpetrators’ motives, which were nationalistic and ethnic, not religious.
Similarly, the vast numbers of genocides (those killed in ethic cleanses, purges, etc. that are not connected to a declared war) are not based on religion. It’s estimated that over 160 million civilians were killed in genocides in the 20th century alone, with nearly 100 million killed by the Communist states of USSR and China. While some claim that Communism itself is a "state religion" — because it has an absolute dictator whose word is law and a "holy book" of unchallenged rules — such a claim simply equates "religion" with the human desire for power, conformance, and control, making any distinctions with other human institutions meaningless"
Read more Is Religion the Cause of Most Wars? | Rabbi Alan Lurie.