Most of the inhabitants of the earth are religious, professing some form of religion.
The largest (by the number of followers) religion of the world is Christianity; throughout the 20th century, the share of Christians in the total population of the Earth remained practically unchanged, remaining equal to 33%. Islam is considered the second world religion (23% of the world’s population). The number of non-believers and atheists is highly controversial and is estimated by various studies at 11-16% of the world’s population. Hindus (14-15%), Buddhists (7%) and supporters of traditional religions make up a significant share of the world’s population.