I have heard the argument that religion is the cause of war, but for religion the world could find a way to live in peace. I find that thought lacking in merit. Since the beginning of recorded history, war has been the pastime of kings and tribal chiefs fighting to defend and extend territory from a position of dominance over their own people. To be chief of chiefs and king of kings you have to, in the words of one recent wannabe dictator, “dominate.” It’s the driving ambition to dominate others that paves the way to war.
Religion, as causation, has seldom been more than a useful crutch. The favor of the gods was sought as a pretext for moral justification. Did chiefs and kings take the gods seriously? I imagine some did, but they all knew that the gods had to be paraded before the people if an army was to be raised and motivated. What ever roles the gods played in getting things off the ground was reinforced by appeals to tribal honor and the glorification of courage in battle against an evil enemy to be subjected to harsh rule or eliminated. The assurance of a god’s help against an evil enemy is the same propaganda appeal made to the emotional fear of the ‘other’ that has motivated military conflicts in our age.
The late medieval and early modern era European wars of religion used religion as the moral justification for plain old greed, selfishness, lust for power, and position. If the masses could be convinced they were doing God’s work, so much the better, but that was just the hook to get things going. There have been exceptions.
The Crusades were, in some sense, religious wars. The lower classes were incited by appeals to recover the Holy Land for Christianity. The upper classes were in it for the glory. Too much of it devolved into barbaric pillaging and murder along the way.
The ancient Islamic empire was created on a religious foundation, but conquered peoples were seldom forced to convert and most established religions were tolerated, their adherents living in reasonable security. The empire was, in the end, about empire not religion. The horrific wars of the 20th century were entirely about empire and global domination on one hand and rebellion against colonialism on the other.
What about Christianity? Political leaders and operatives have often used appeals to promote or defend Christianity to whip up emotional fervor for war. But the prophetic theme of holy scripture, the life, teaching and example of Jesus Christ, and the inspired guidance offered through the letters to the early church by his apostles go in another direction. They reveal that God’s way is for healing, reconciliation, economic and social justice that works for peace on earth and good will to all humanity. They take the form of commandments, not sentimental platitudes. To believe that Jesus is the Word of God made flesh who was crucified, died, and is resurrected, and to follow Christ in his way of love provides no excuse for war or the justification of war.
Humanity, it turns out, has proven itself unable and unwilling to live in harmony. To accommodate the predictable outcome of humanity’s brokenness taking the form of greed and lust for power, the church worked out a just war theory. Yet, a just war theory cannot defend war as a moral good. It can only minimize the evil when war is the lesser of evils that cannot be avoided.