Who are the nonreligious? Depending on how they are counted, the nonreligious today may be considered the world’s third largest ‘religion,’ trailing only Christianity and Islam. They exercise an increasingly influential voice on issues from the immigration crisis in Europe to secular-religious tensions in Asia Pacific. Now a developing body of research is shedding critical light on the diversity and complexity of this group in an age when the makeup and balance of religious and nonreligious populations, along with their shared history, matters in ways both small and large.

The global refugee crisis represents a potential transformational moment in world history. Nations from Africa to Asia to Europe to North America with troubled pasts of ethnic conflict and of putting political and economic self-interest above humanitarian needs have an opportunity to write new chapters in their national stories. Religion is playing and will play a critical role.