Nigeria is the most populous black nation on earth. Among its chief blessings are oil and a large array of religious, tribal and language groups. Yet conflict, violence and terrorism are part of reality there, too. …

In earlier times, armies clashed over territory. Objectives were clear, as was the identity of the “enemy,” lurking beyond a defined border. Nowadays people in too many parts of the world are taught to identify as the enemy neighbors who are indistinguishable from themselves, save by their beliefs. They have to be “selected” before they can be butchered. Whatever the original cause of a conflict, once religion becomes the driving ideological tool, it is no longer just about oil reserves or farmland.

Today, Islamist extremists’ rage has the power to transform small, local conflicts into infernos that can snuff out lives thousands of miles away. Threatened targets of religious hatred today include Hindus, Sunnis, Shiites, Bahais and Jews, but the most widely menaced are Christians. A Pew Forum study last year found that Christians are persecuted—by independent groups or governments—in 131 of the 193 countries in the world.

We cannot cure religious strife, but we must take action to forestall ever-increasing murder and mayhem in the name of God. International bans against blasphemy, offensive cartoons and videos will do nothing to stem the tide.