As of 2015, there are an estimated 4,200 different religions in the world. Listed below are the largest and best-known religions by the date each was formed:
Start date Membership
Judaism 2000BC 17 million
Hinduism 1500BC 1,000 million
Buddhism 523BC 500 million
Chinese Folk Religion 270BC 400 million
Christianity 30AD 1,900 million
Islam 622AD 1,600 million
No Religion 775 million
Atheists 150 million
All others – including Tribal religions, Shikhism, Taoism, Baha’I, and Shinto etc. have approximately 150 million followers.
One really interesting data point is that there are only 17 million Jews in the world. Six million live in Israel, six million live in the USA and the remaining 5 million are spread throughout the world.
Many of the major religions noted above are subdivided into separate sub-groups (eg. there are 34,000 different forms of Christianity). Many religious sub-groups have long-term disagreements with each other which has led to violence and war (eg: in Islam there are on-going wars between the Sunni and Shia; in Christianity there were many wars between Roman Catholics, Greek Orthodox Catholics, Protestants, and Lutherans).