The vast majority, about 80%, of the Indian population is Hindu. The second most popular religion in India is Islam. Other popular Indian religions include Christianity, Sikhism, Buddhism, Janism, and Zoroastrianism.

Hinduism is considered the oldest religion in the world and was developed around 2500 BCE. It has close to one billion followers and is the third largest religion in the world. It is a polytheistic religion with a variety of mythologies and gods. The Hindu holy text is known as the Vedas which is considered to be constantly evolving.

Different sects within Hinduism have different beliefs. For example, the Smartism sect believes that worship can be conducted in numerous ways while the Vaishnava sect believes only worship of the god Vishu is important.

Islam, the second largest religion in the world, is a monotheistic religion that arrived in India in the 600s. It's holy text, the Quran, is believed to be the word of God as revealed to the prophet Mohammed through the angel Gabriel.

Islam is comprised of two sects, Sunni and Shia. Most of India's muslims, like the world's muslims, are Sunni. While the two sects are largely similar, they do hold some different beliefs. One distinction between these two sects is that the Shias require that religious leaders be descendants of the prophet Muhammed.

Christianity is believed to have arrived in India between 50 and 90 CE. It is a monotheistic religion that focuses on Jesus as the messiah. The arrival of European explorers in the 16th century introduced Roman Catholicism which is especially popular in South and Northeast India, especially in the states of Meghalava, Nagaland and Mizoram.

Sikhism began to surface in the 16th century in Northern India and are primarily concentrated in the Indian province of Punjab. Sikhism is a monotheistic religion which follows the teachings of ten Gurus, or religious leaders. Sikhs adhere to a concept known as the five Ks which are five articles of faith. These five articles, a turban, comb, bracelet, special undergarment, and a sword, are worn at all times to symbolize one's faith.

Buddhism , meaning teachings of the awakened one, developed around the 5th century and had a large influence on the development of religious beliefs in India. Buddhism is an atheistic religion based on the teaching of Siddhartha Gotama, or Siddartha Gautama, who was born in modern-day Nepal. The focus in this religion is the attainment of nirvana through meditation.

Jainism began as a religion in ancient India. Like Buddhism it is atheistic religion or philosophy. It holds that there is equality among all living things and focuses on the principle of non-violence. Followers of Jainism compose a relatively small number of Indians who are generally very affluent.

Zoroastrianism is a religion and philosophy based on Ahura Mazda as God, and is relayed through the teachings of the prophet Zoraster. It's central, sacred text is known as the Avesta. Zoroastrianism arrived in India from Persia around 650 BCE. One belief of this religion is that the universe is presently in the phase of coming closer to perfection as a result of people's good deeds. Indians that practice this religion are known as Parsis'.