Worldwide, more than eight-in-ten people identify with a religious group. A comprehensive demographic study of more than 230 countries and territories conducted by the Pew Research Center’s Forum on Religion & Public Life estimates that there are 5.8 billion religiously affiliated adults and children around the globe, representing 84% of the 2010 world population of 6.9 billion. …
At the same time, the new study by the Pew Forum also finds that roughly one-in-six people around the globe (1.1 billion, or 16%) have no religious affiliation. This makes the unaffiliated the third-largest religious group worldwide, behind Christians and Muslims, and about equal in size to the world’s Catholic population. [cont.]
Pew