Since the late 19th century the demographics of religion have changed worldwide. There is no really clear data available on how many religions there are in this world, nor on how many people profess to follow each religion. But, taking approximate figures, these are the 10 religions which have the most followers.

1. Christianity  –  approximately  2.1 biillion
Christianity is based on the Old Testament and the teachings of Jesus of Nazareth. Their Scriptures are called The Bible, including the Old and New Testament. They have many sub-sects, but the three main ones are Roman Catholics, Protestants and Eastern Orthodoxy.

2. Islam  –  approximately 1.3 billion
Islam is a monotheistic religion, derived from the teachings of Mohammed, a 7th century Arab religious figure. The Qurán and the Sunnah are regarded as the main sources of their beliefs. There are two major denominations in Islam – Shia and Sunni.

3. Hinduism –  approximately  851 million
The world’s oldest organised religion, it has no founder as such, since it is a combination of various beliefs and tenets. Their main scriptures are the Vedas and the Upanishads, The Bhagavad Gita, excerpted from the Mahabharata is considered to be the summary of their ancient teachings and beliefs.

4. Buddhism  –  approximately 385 million
Gautam Buddha or the enlightened one founded this religion in India in 5th century BC. There are many sects to Buddhism, but they all believe in four basic principles – That Buddha is their teacher: that they all follow the Middle way; that both monks and laymen can teach you how to achieve enlightenment; and that Buddhahood is the highest seat they can attain.

5. Sikhism  –  approximately 25 million
Guru Nanak, Sikhism’s first Holy Guru founded the religion in the late 15th century. He was followed by a lineage of nine other Gurus, and their religious scripture the Adi Granth was written by their fifth Guru. Their focus of worship is this Holy Book, which is placed in all their places of worship and their homes.