World Religions or belief systems by number of adherents

1. Christianity 2 billion
• Roman Catholicism : 1.1 billion
• Protestantism : 360 million
• Eastern Orthodoxy : 220 million
• Anglican : 84 million
• Other Christians : 280 million
2. Islam 1.4 billion
• Sunnism : 940 million
• Shiism 120 million
3. Secular/Nonreligious/Agnostic/Atheist 1.1 billion
4. Hinduism 900 million
5. Buddhism 360 million
6. Chinese traditional religion 225 million
• Not a single organized religion includes elements of Taoism , Confucianism , and traditional non scriptural religious observance.
7. Primal indigenous 150 million
• Not a single organized religion includes a wide range of primarily Asian traditional or tribal religions, including Shamanism and Paganism.
8. African Traditional and Diasporic 95 million
• Not a single organized religion, this includes traditional African beliefs such as Yoruba as well as Diasporic beliefs such as Santeria and Vodoun.
9. Sikhism 23 million
10. Juche 19 million
• Not considered a religion by adherents. Juche is the political ideology taught by North Korean communists; some have argued it constitutes a religion.
11. Spiritism 14 million
• Not a single organized religion includes a variety of beliefs including some forms of Umbanda.
12. Judaism 14 million
13. Bahá'í Faith 5 million
14. Jainism 4 million
15. Shinto 4 million
16. Cao Dai (mainly Vietnamese) 3 million
17. Tenrikyo 2.4 million
18. Neopaganism 1 million
19. Unitarian Universalism 800,000
20. Rastafarianism 600,000
• Not an organized religion
21. Scientology 500,000
22. Zoroastrianism 150,000

• Source of statistics: adherents.com  ( http://www.adherents.com/Religions_By_Adherents.html ), updated 2005. These statistics are based on analysis of a range of sources on religious populations, for more on the methodology; please see Adherent.com's explaination