Some very interesting, and generally not surprising, information in this survey from the Pew Research Center.
“The demographic study – based on analysis of more than 2,500 censuses, surveys and population registers – finds 2.2 billion Christians (32% of the world’s population), 1.6 billion Muslims (23%), 1 billion Hindus (15%), nearly 500 million Buddhists (7%) and 14 million Jews (0.2%) around the world as of 2010. In addition, more than 400 million people (6%) practice various folk or traditional religions, including African traditional religions, Chinese folk religions, Native American religions and Australian aboriginal religions. An estimated 58 million people – slightly less than 1% of the global population – belong to other religions, including the Baha’i faith, Jainism, Sikhism, Shintoism, Taoism, Tenrikyo, Wicca and Zoroastrianism, to mention just a few”
“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.”
In the summary on Huffington Post:
“REUTERS – People with no religious affiliation make up the third-largest global group in a new study of the size of the world’s faiths, placing after Christians and Muslims and just before Hindus.”
“Among the 1.1 billion unaffiliated people around the world, over 700 million, or 62 percent of them, live in China alone, where they make up 52.2 percent of the Chinese population.
Japan comes next with the second largest unaffiliated population in the world with 72 million, or 57 percent of the national population. After that comes the United States, 51 million people — 16.4 percent of all Americans — said they have no link to an established faith.”