Largest world faith is Christianity, followed by Islam, then Atheism

http://www.dailymail.co.uk/news/article-2250096/You-wouldnt-believe-atheism-worlds-biggest-faith-Christianity-Islam.html
Christianity is the largest faith with 2.2 billion adherents or 31.5 per cent of the world's population
There are about 1.6 billion Muslims around the world - or 23 per cent of the global population
People with no religious affiliation now make up the third-largest global group in a new study of the world's faiths - coming after Christians and Muslims but just before Hindus.
The study, based on extensive data for the year 2010, also showed Islam and Hinduism are the faiths most likely to expand in the future while Judaism has the weakest growth prospects.
It showed Christianity is the most evenly spread religion, present in all regions of the world, while Hinduism is the least global with 94 per cent of its population in one country, India.

 

Overall, 84 per cent of the world's inhabitants, which it estimated at 6.9 billion, identify with a religion, according to the study entitled 'The Global Religious Landscape' issued by the Pew Forum on Religion and Public Life on Tuesday.
The 'unaffiliated' category covers all those who profess no religion, from atheists and agnostics to people with spiritual beliefs but no link to any established faith.
'Many of the religiously unaffiliated do hold religious or spiritual beliefs,' the study stressed.
'Belief in God or a higher power is shared by 7 percent of unaffiliated Chinese adults, 30 per cent of unaffiliated French adults and 68 percent of unaffiliated U.S. adults,' it said.
Pew Forum demographer Conrad Hackett said the 2,500 censuses, surveys and population registers used to compile the report did not allow a further breakdown to estimate the world population of atheists and agnostics.
'It's not the kind of data that's available for every country,' he said. 'A census will typically ask what your religion is and you can identify a number of particular affiliations or no religion.
'An age breakdown showed Muslims had the lowest median age at 23 years, compared to 28 for the whole world population. The median age highlights the population bulge at the point where half the population is above and half below that number.
'Muslims are going to grow as a share of the world's population and an important part of that is this young age structure,' Hackett said.

 

By contrast, Judaism, which has 14 million adherents or 0.2 per cent of the world population, has the highest median age at 36, meaning its growth prospects are weakest.
Hackett noted that Israel, which has 40.5 percent of the world Jewish population, had a younger age structure than the United States, where 41.1 percent of the world's Jews live.
Global Christianity's median age is 30 and Hinduism's 26. With a median age of 34, the growth prospects for religiously unaffiliated people are weak, the study showed.
The study estimated Christianity was the largest faith at 2.2 billion adherents or 31.5 percent of the world's population.
The Roman Catholic Church makes up 50 per cent of that total, with Protestants - including Anglicans and non-denominational churches - at 37 percent and Orthodox at 12 percent.
There are about 1.6 billion Muslims around the world, or 23 per cent of the global population. 'The overwhelming majority (87-90 percent) are Sunnis, about 10-13 per cent are Shia Muslims,' the study said.
Among the 1.1 billion unaffiliated people around the world, 62 per cent live in China alone and 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, where 16.4 percent of all Americans said they have no link to an established faith.
The world's Hindu population is concentrated mostly in India, Nepal and Bangladesh. Half of the world's Buddhists live in China, followed far behind by Thailand at 13.2 per cent of the world Buddhist population and Japan with 9.4 per cent.
The study found that about 405 million people, or about 6 per cent of the world population, followed folk religions such as those found in Africa and China or among Native American and Australian aboriginal peoples.
Another 58 million, or nearly 1 percent of the world population, belonged to 'other religions' including Baha'i, Taoism, Jainism, Shintoism, Sikhism, Tenrikyo, Wicca and Zoroastrianism. Most were in the Asia-Pacific region.