rank religions adherents (1994) % of total 1 Christianity 1,900,174,000 33.6 - Roman Catholic 1,058,069,000 18.7 - Protestant 391,143,000 6.9 - Orthodox 174,184,000 3.1 - Anglican 78,038,000 1.4 - Other Christians 199,707,000 3.5 2 Islam 1,033,453,000 18.3 3 Hinduism 764,000,000 13.5 4 Buddhism 338,621,000 6.0 5 Chinese folk religion 149,336,000 2.6 6 New-Religions 128,975,000 2.3 7 Tribal religion 99,150,000 1.8 8 Sikh 20,204,000 0.4 9 Judaism (Jews) 13,451,000 0.2 10 Shamanism 11,010,000 0.2 11 Confucianism 6,334,000 0.1 12 Baha'i 5,835,000 0.1 13 Jain 3,987,000 0.1 14 Shintoism 3,387,000 0.1 Other religions 20,419,000 0.4 Nonreligious 924,078,000 16.3 Atheism 239,111,000 4.2 total population 5,661,525,000 100.0 Adherents: As defined and enumerated for each of the world's countries in World Christian Encyclopedia (1982), projected to mid-1994; adjusted for recent data. Other Christians: Catholics (non-Roman), marginal Protestants, crypto-Christians, and adherents of African, Asian, black, and Latin-American indigenous churches. Islam: 83% Sunnites, 16% Shi'ites, 1% other schools Hinduism: 70% Vaishnavites, 25% Shaivites, 2% neo-Hindus and reform Hindus. Buddhism: 56% Mahayana, 38% Theravada (Hinayana), 6% Tantrayana (Lamaism). New-Religions: Followers of Asian 20th-century New Religions, New Religious movements, radical new crisis religions, and non-Christian syncretistic mass religions, all founded since 1800 and most since 1945. Confucians: Non-Chinese followers of Confucius and Confucianism, mostly Koreans in Korea. Other religions: Including 70 minor world religions and a large number of spiritist religions, New Age religions, quasi religions, pseudo religions, parareligions, religious or mystic systems, religious and semireligious brotherhoods of numerous varieties. Nonreligious: Persons professing no religion, nonbelievers, agnostics, freethinkers, dereligionized secularists indifferent to all religion. Atheists: Persons professing atheism, skepticism, disbelief, or irreligion, including antireligious (opposed to all religion). Total Population: United Nations medium variant figures for mid-1994.

From what I have learned in my World Religion class, the main religions are Christianity, Islam, Judaism, Buddhism, and Hindu. Most all religions have similar root beliefs. Be good to man and earth. That statement pretty much sums up a lot of it. They just have different rules of how to go about doing that.