Are there stats that shows how many christians, muslims, hindu, people and so on on this planet ;)?

Answer 1

Yes. These may not be 100% correct but there are statistics available.

Christianity: 2.1 billion
Islam: 1.3 billion
Secular/Nonreligious/Agnostic/Atheist: 1.1 billion
Hinduism: 900 million
Chinese traditional religion: 394 million
Buddhism: 376 million
primal-indigenous: 300 million
African Traditional & Diasporic: 100 million
Sikhism: 23 million
Juche: 19 million
Spiritism: 15 million
Judaism: 14 million
Baha'i: 7 million
Jainism: 4.2 million
Shinto: 4 million
Cao Dai: 4 million
Zoroastrianism: 2.6 million
Tenrikyo: 2 million
Neo-Paganism: 1 million
Unitarian-Universalism: 800 thousand
Rastafarianism: 600 thousand
Scientology: 500 thousand

Answer 2

1. Christianity 2.1 billion
2. Islam 1.3 billion
3. Secular/Irreligious/Agnostic/Atheist 1.1 billion
4. Hinduism 900 million
5. Chinese folk religion 394 million
6. Buddhism 376 million, not including Chinese folk Religion (see also Buddhism by country)
7. Primal indigenous ("Pagan") 300 million
8. African traditional and diasporic 100 million
9. Sikhism 23 million
10. Juche 19 million
11. Spiritism 15 million
12. Judaism 14 million
13. Bahá'í Faith 7 million
14. Jainism 4.2 million
15. Shinto 4 million (see below)
16. Cao Dai 4 million
17. Zoroastrianism 2.6 million
18. Tenrikyo 2 million
19. Neo-Paganism 1 million
20. Unitarian Universalism 800,000
21. Rastafari movement 600,000


http://en.wikipedia.org/wiki/Religion

Answer 3

Yes there are. CIA's factbook is an excellent source:

Christians 33.03% (of which Roman Catholics 17.33%, Protestants 5.8%, Orthodox 3.42%, Anglicans 1.23%), Muslims 20.12%, Hindus 13.34%, Buddhists 5.89%, Sikhs 0.39%, Jews 0.23%, other religions 12.61%, non-religious 12.03%, atheists 2.36% (2004 est.)

Answer 4

I'm not sure about the world, but I know you can find how many are in the U.S. You can find that info by visiting the U.S. Census Bureau website.