This list appeared in The Christian Science Monitor as the "Top 10 Organized Religions in the World" (August 4, 1998, edition, on page
B2)
NOTE from Preston, Adherents.com: I had not seen this list from the Christian Science Monitor until after I had developed my own listing. It may be noted that the relative order here is identical to my listing. But in choosing to list only the "top 10 organized religions," there are groups (Chinese folk religion, secular groups, primal-indigenous, and groups smaller than the top ten), not listed in this list which I have in my list. Like most such lists, the original source of this data is probably the Encyclopedia Brittanica and/or Barret's World Christian Encyclopedia.
Religion
Members
-------------------- ----------------------
Christianity
1.9 billion
Islam
1.1 billion
Hinduism
781 million
Buddhism
324 million
Sikhism
19 million
Judaism
14 million
Baha'ism
6.1 million
Confucianism
5.3 million
Jainism
4.9 million
Shintoism
2.8 million
Thanks to Mike Muttart for posting this list on the web and generating this HTML.