What are the top world religions by the amount of followers?

This question is difficult to answer for a number of reasons:

1. The idea of religion: what is a religion? Buddhism is often considered a religion, but many note it is actually an ideal way of life (as are most religions) but their is no diety in Buddhism.

2. Differant Sects: Religion today has splintered so many times that it is difficult to group the large differant groups. In Western Christian Religions over 50 differant sects exist in the United States today all steming originally from The Holy Orthodox Church. Islam is very similar where the major groups are Shi'a or Sunni, but differing regions have differing religions as well

Many people believe that these following are the most accurate Numbers

1. Christianity (Roman Catholic is highest then Eastern Orthdox, Lutheran, Anglican)

2. Islam (Sunni, Shi'a)

3. Hinduism

4. Buddhism (if considered a religion)

5. Judaism

6. Shinto or Taoist

7. Indigenious beliefs

8. Athiest or Agnostic