Religious wars are endemic in our time, which is a time with little care for reverence. Perhaps these wars are cooling down in some places, but they are heating up in others, even as I write this book. If a religious group thinks it speaks and acts as God commands in all things, this is a failure of reverence. A group like that may turn violent and feel they are doing so in good faith. Nothing is more dangerous than that feeling.

War is nothing new, and neither are killer strains of religion, pathogens that take hold of a people and send them into paroxysms of violence. War and religion will always be with us; we can't expect to shake them off. But we can ask what it is in religion that might keep the dogs of war on leash, and what it is that whips them into a frenzy and lets them loose. It is reverence that moderates war in all times and cultures, irreverence that urges it on to brutality. The voices that call in the name of God for aggressive war have lost sight of human limitations. They have lost reverence, even when they serve a religious vision. So it is when a people believe that their god commands them to take land from others, or insists that they force others into their way of thinking. Even when the goal of war is something as noble as freedom or peace, it may be irreverent to think we can impose these goals by violence.

When Agamemnon waited on the beach with his ships and chariots and with the men who hungered to capture Troy, the winds remained hostile, and he asked a diviner what he should do. He had faith in his diviner, and the diviner had faith in his power to speak for the gods. He said he knew what the gods desired the life of the king's daughter. And so Iphigenia came, summoned to her wedding in all the veiled finery of a bride. At the altar stood her father with the priest. But there was no young husband, only the great sharp knife poised to end her life.

The poet Lucretius tells this tale, as I have done, to be the introduction for his work of philosophy. He ends with the strong line, tantum religio potuit suadere malorum (1.101)--"so great is the power of religion to lead us to evil." He gives us Iphigenia to stand for all the huge unholy cost of war when it is driven by men who believe they know what the gods want. But he does not mean to condemn everything that falls under religion. Lucretius may be hostile to some kinds of faith, but he begins his work with an invocation to the goddess who stands for Nature. He too is a poet of reverence.

Reverence runs across religions and even outside them in and through the fabric of any community, however secular. We may be divided from one another by our beliefs, but never by reverence. If you desire peace in the world, do not pray that everyone share your beliefs. Pray instead that all may be reverent.