Hinduism is the oldest and largest religion in India. The religion is complex, as it follows many rules and has thousands of Gods. A major Hindu belief is that every person possesses a soul which has been reincarnated and passed from generation to generation. The Hindu religion is deeply rooted in Indian society with their belief in the caste system. This system has rigid social barriers and assigns individuals to castes based on their occupation. The Hindu belief is that castes are determined by one's "karma," or all the good and bad things accumulated by the soul. Only by obeying one's "dharma," or righteous life path, can one finally reunite with the universal spirit, Brahman. Because of this belief, Hindus are encouraged to obey the caste system rules in order to ensure that their soul can slowly rise in caste ranks and finally reunite with Brahman. Hinduism is practiced mainly in South Asia and has not spread very much out of India.

Buddhism also originated in India, and now is a wide-spread, global religion. It is based on the teachings of Siddhartha Gautama. He assumed the title of Buddha after finding enlightenment. Buddha found that the reasons for suffering were that we want what we don't have, we want to keep what we have, and we don't want what we don't like. He taught that it was possible to reach Nirvana, or perfect peace, in a lifetime if one follows the 8 fold path and takes the middle path in life. Buddhism appealed to many Hindus because of its simplicity and belief that one is only responsible for their own life and not all the lives of their soul.

Jainism is a very small, reclusive religion in India. It was founded in 420 BC by the scholar Vardhamana. This religion challenges the caste system of Hinduism, but believes in karma, reincarnation and enlightenment. Many Jains practice fruitarianism and non-violence because they believe any harm against a living thing is bad for one's karma. Although Jainism only has a small following, it was one of the first religions to challenge Hinduism in India.

Christianity was brought to India when Portugese and British Catholic/Protestant missionaries came into South Asia. The climax of its influence was during the British occupation, when many churches were built by missionaries. The religion of Christianity has one God and Christians believe in Jesus, the Son of God, and Heaven. Many of India's lower caste system citizens were keen on converting to Christianity because this religion only gave punishment for one's own sins instead of the karma carried by the soul. Today, Christianity is mostly found in the south of India.

Islam was founded in Mecca by Muhammad the Prophet. India is currently the world's 4th largest Muslim nation. Islam spread from the Arabian Peninsula to North Africa, and then to India. The Muslims believe that all human beings are equal, and they oppose the caste system. Because of this, they have often been in conflict with the Hindus. There is only one God in their religion, as opposed to the many Gods of the Hindu religion. Throughout history, the differences in belief between Hindus and Muslims have led to violence, but Muslims now are granted equal rights in terms of the law. Many lower caste system civilians have converted to Islam because of its appealing appealing belief about the equality of humanity.

The Sikhism religion was founded in  modern-day Pakistan, specifically in the Punjab area. The religion has one God with many names and no human form. Prayer is essential to the religion, as Sikhs pray many times every day. They have similar beliefs to the Hindus in that they believe in karma and reincarnation. However, Sikhism, like many other religions in India, reject the Hindu caste system. Nowadays, Sikhs are generally known not only as a group of people with a certain religious following, but also as skilled militants.