The much-maligned doctrine of original sin has an unexpected consequence. To see this, contrast the situations in classic Islam with orthodox Christianity. In both religions, if you abandon unbelief and follow God you find forgiveness and join the community of believers. But Islam holds that every child is born a Muslim and subsequently rejects God's way. It is therefore possible for a man to have been born a Muslim, raised a Muslim, and never been an infidel. To such a man an unbeliever is a traitor--different in kind from himself. But a Christian, even one raised in the church, is told that he was a rebel once himself; and the unbeliever--though a rebel against the truth--is not that different from what he used to be.

Xenophobia is always a factor in relations between communities, but for the most devout Christian there must be an element of empathy, while for the most devout Muslim there must be a sense of betrayal.