‘Billions of people share your belief that the creator of the universe wrote (or dictated) one of our books. Unfortunately, there are many books that pretend to divine authorship, and they make incompatible claims about how we all must live. Competing religious doctrines have shattered our world into separate moral communities, and these divisions have become a continual source of human conflict.
In response to this situation, many sensible people advocate something called religious tolerance. While religious tolerance is surely better than religious war, tolerance is not without its problems. Our fear of provoking religious hatred has rendered us unwilling to criticize ideas that are increasingly maladaptive and patently ridiculous. It has also obliged us to lie to ourselves—repeatedly and at the highest levels of discourse—about the compatibility between religious faith and scientific rationality. Our competing religious certainties are impeding the emergence of a viable, global civilization. Religious faith—faith that there is a God who cares what name He is called, faith that Jesus is coming back to earth, faith that Muslim martyrs go straight to Paradise—is on the wrong side of an escalating war of ideas.
Religion raises the stakes of human conflict much higher than tribalism, racism, or politics ever can, as it is the only form of in-group/ out-group thinking that casts the differences between people in terms of eternal rewards and punishments. One of the enduring pathologies of human culture is the tendency to raise children to fear and demonize other human beings on the basis of religious faith. Consequently, faith inspires violence in at least two ways. First, people often kill other human beings because they believe that the creator of the universe wants them to do it. Islamist terrorism is a recent example of this sort of behavior. Second, far greater numbers of people fall into conflict with one another because they define their moral community on the basis of their religious affiliation: Muslims side with other Muslims, Protestants with Protestants, Catholics with Catholics. These conflicts are not always explicitly religious. But the bigotry and hatred that divide one community from another are often the products of their religious identities. Conflicts that seem driven entirely by terrestrial concerns, therefore, are often deeply rooted in religion. The fighting that has plagued Palestine (Jews vs. Muslims), the Balkans (Orthodox Serbians vs. Catholic Croatians; Orthodox Serbians vs. Bosnian and Albanian Muslims), Northern Ireland (Protestants vs. Catholics), Kashmir (Muslims vs. Hindus), Sudan (Muslims vs. Christians and animists), Nigeria (Muslims vs. Christians), Ethiopia and Eritrea, (Muslims vs. Christians), Ivory Coast (Muslims vs. Christians), Sri Lanka (Sinhalese Buddhists vs. Tamil Hindus), Philippines (Muslims vs. Christians), Iran and Iraq (Shiite vs. Sunni Muslims), and the Caucasus (Orthodox Russians vs. Chechen Muslims; Muslim Azerbaijanis vs. Catholic and Orthodox Armenians) are merely a few, recent cases in point.
 This long-standing civil war is distinct from the genocide that is currently occurring in the Darfur region of Sudan.
And yet, while the religious divisions in our world are self-evident, many people still imagine that religious conflict is always caused by a lack of education, by poverty, or by politics. Most nonbelievers, liberals, and moderates apparently think that no one ever really sacrifices his life, or the lives of others, on account of his religious beliefs. Such people simply do not know what it is like to be certain of Paradise. Consequently, they can’t believe that anyone is certain of Paradise. It is worth remembering that the September 11 hijackers were college educated, middle class people who had no discernible experience of political oppression. They did, however, spend a remarkable amount of time at their local mosque talking about the depravity of infidels and about the pleasures that await martyrs in Paradise.’
– Harris. S. 2006. Letter To A Christian Nation p. 25-26