01.Christianity: 2 billion
02.Islam: 1.3 billion
03.Hinduism: 900m
04.Atheist: 850m
05.Buddhism: 360m
06.Chinese traditional religion: 225m
07.primal-indigenous: 150m
08.African Traditional & Diasporic: 95m
09.Sikhism: 23m
10.Juche: 19m
11.Spiritism: 14m
12.Judaism: 14m

 

13.Baha'i: 6m
14.Jainism: 4m
15.Shinto: 4m
16.Cao Dai: 3m
17.Tenrikyo: 2.4m
18.Neo-Paganism: 1m
19.Unitarian-Universalism:800-thousand
20.Scientology: 750 thousand
21.Rastafarianism: 700 thousand
22.Zoroastrianism: 150 thousand

*Statistics provided by Adherents.com