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.
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 war argue that the Crusades started because the European aristocracy and the Pope wanted to increase their wealth and conquering Palestine seemed an easy solution. Moreover, the Pope wanted to broaden the limits of the power of the Catholic church by converting numerous Jews and Muslims to Christianity. Some researchers say that the massacre of the 3000 Christians which caused the Crusades to begin was not because of differing religious beliefs.
Even if all of the above were true, it does not alter the fact that after its non-religious beginning the Crusades were fought for two hundred years as a Holy War. According to Wikipedia, religious war (Latin: bellum sacrum) is a war caused by, or justified by, religious differences. It can involve one state with an established religion against another state with a different religion or a different sect within the same religion, or a religiously motivated group attempting to spread its faith by violence, or to suppress another group because of its religious beliefs or practices.
Accordingly, whether or not it begin at the behest of a greedy European aristocracy or a power-hungry pope, the Crusades, which were justified by religious differences, is the very definition of religious war. No one knows exactly how many people died during the nine Crusades, but it is known to be one of histories bloodiest wars over religion.
The series of wars known as the European wars followed the onset of the Protestant Reformation in Western and Northern Europe. The combatants in these series of wars were often not neatly divided by religion and sometimes were altogether unconnected; yet all of these wars were strongly influenced by the religious change of the period, and the conflict and rivalry that it produced.
Indeed, the list of medieval wars that are frequently cited as religious wars are numerous and include the Muslim conquests (7th to 19th centuries), and the Spanish Reconquista (8th to 15th centuries). But what of contemporary wars that are not frequently cited as religious, such as World War II or the American Civil War? Do those wars meet the definition of a bellum sacrum? Let us see.
Religious differences during the period of time coinciding with WWII led to discord between the people of Europe, whereby the Nazi Party rose upon a particular man’s religious views.
A passage from Adolf Hitler’s Mein Kampf states, “…today I believe that I am acting in accordance with the will of the Almighty Creator: by defending myself against the Jew, I am fighting for the work of the Lord.” The Nazi Party blamed the Jewish people for the loss of World War I. It is beyond argument that by 1945, the genocide of six million Jewish people had been committed as a direct result of Hitler’s religious views. Bellum sacrum.
With respect to the American Civil War, Wikipedia references a body of scholarship, led by Mark Knoll, that has highlighted the fact that the American debate over slavery became a shooting war in part because the two sides reached diametrically opposite conclusions based on reading the same authoritative source of guidance on moral questions: the King James Version of the Bible.
Specifically, the pro-slavery South could point to slaveholding by the godly patriarch Abraham (Gen 12:5; 14:14; 24:35–36; 26:13–14), a practice that was later incorporated into Israelite national law (Lev 25:44–46). It was never denounced by Jesus, who made slavery a model of discipleship (Mk 10:44). The Apostle Paul supported slavery, counseling obedience to earthly masters (Eph 6:5–9; Col 3:22–25) as a duty in agreement with “the sound words of our Lord Jesus Christ and the teaching which accords with godliness” (1 Tim 6:3). Because slaves were to remain in their present state unless they could win their freedom (1 Cor 7:20–24), he sent the fugitive slave Onesimus back to his owner Philemon (Phlm 10–20).
The Bible, interpreted under these assumptions, seemed to clearly suggest that slavery was Biblically justified.
Modern historians differ somewhat on the relationship between religion and southern sectionalism, however. Christine Leigh Heyrman, in Southern Cross: The Beginnings of the Bible Belt (1997), utilizing journals of late 18th and early 19th century Baptist and Methodist ministers, concludes that religious leaders accommodated slavery in order to gain ground in the South. Even if looked at through the lens of sectionalism, it is beyond debate that religion heavily influenced the American Civil War. That places it squarely within the parameters of Wikipedia’s definition of religious war.