What is the world population that believe in Christianity?

Answer 1

The world population that believe in Christianity are around 2100 millions as of year 2000.

[Ref:David Barrett et al, "World Christian Encyclopedia: A comparative survey of churches and religions - AD 30 to 2200," Oxford University Press, (2001)]

Answer:About 33% of the world's population are nominally Christians, it is difficult to establish who actually believes in the tenets of a religion. The top 12 religions are listed below, the list includes the "major" religions (Abrahamic religions, Hinduism and Buddhism)

1. Christianity: 2.1 billion
   
2. Islam: 1.5 billion
   
3. Secular/Nonreligious/Agnostic/Atheist: 1.1 billion
   
4. Hinduism: 900 million
   
5. Chinese traditional religion: 394 million
   
6. Buddhism: 376 million
   
7. primal-indigenous: 300 million
   
8. African Traditional & Diasporic: 100 million
   
9. Sikhism: 23 million
   
10. Juche: 19 million
    
11. Spiritism: 15 million
    
12. Judaism: 14 million

Answer 2

As of the early 21st century, Christianity has around 2.2 billion adherents

-Wikipedia