Christians need to learn more about Islam—a lot more. The religion has more than 1.6 billion adherents. Some of them—but not all—have engaged in terrible acts of violence against Christians in the Middle East, North Africa and Asia. The main perpetrators in the murder of more than 2 million Christians in the Anatolian Peninsula between 1915 and 1922 were Islamic. Muslim-majority countries have also been significant sources of anti-Jewish invective in the modern world. In fact, leaders of these countries have tried to destroy the Jewish state on a number of occasions since its creation in 1948.