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. Surveys indicate that many of the unaffiliated hold some religious or spiritual beliefs (such as belief in God or a universal spirit) even though they do not identify with a particular faith.
On the nature of the "unaffiliated
The religiously unaffiliated are heavily concentrated in Asia and the Pacific, where more than three-quarters (76%) of the world’s unaffiliated population resides. The remainder is in Europe (12%), North America (5%), Latin America and the Caribbean (4%), sub-Saharan Africa (2%) and the Middle East and North Africa (less than 1%).