Religion Statistics

Christianity:                                
CIA- 31.4%
Adherents- 33%

Islam:
CIA- 23.2%
Adherents- 21%

Hinduism:
CIA- 15%
Adherents- 14%

Buddhism:
CIA- 7.1%
Adherents- 6%

Judaism:
CIA- 0.2%
Adherents- 0.22%

The CIA World Factbook and Adherents.com statistics are very close to each other for the percentage of the five major religions in the world. Islam, Hinduism, and Buddhism seem to be growing because the adherents.com information is from 2005, but Christianity and Judaism are a little less than it was in 2005.