Hindu :
The word Hindu originally meant people living on the banks of the river Sindhu. Now it has religious-cum-philosophical connotations. The roots of Hindu Philosophy are the ideas of the Vedas. The Vedas are called Shruti or `that which is heard' and are regarded as revelations to sages passed down orally to disciples and students. Such ideas led to the Samkhya system of philosophy, which is astik (Theist), rational and systematic in its approach. The sage Kapila of 7th century BC is considered to be its founder.

Christianity :
Christianity is not native to the Indian soil, although there have been Christian communities in Kerala almost since the founding of the religion by Jesus Christ. Born in Bethlehem, to Mary and Joseph (who was a carpenter), Jesus spread love and mercy to all. In the environment of the Roman Empire, his message acquired a unique force of its own, the powers-that-be had him crucified after he had been betrayed to them by one of his own disciples. But he rose from his tomb and this Resurrection gave new strength to his other followers, who went on spreading his message.

Sikhism :
Sikh philosophy is a young, indigenous, monotheistic one. Guru Nanak (1469-1539) who was trying to unite Hinduism and Islam, founded the Sikh religious order. The word `Sikh' derives from the Sanskrit word shishya or disciple. Sikh philosophy is a set of ideas developed by ten gurus or teachers and passed on to their shishyas or disciples. It conceives of God as nirakara or formless and also as one. It admits of no idols or superstitions, whether Hindu or Islamic. It recognizes all human beings to be equal. However it retains certain Hindu ideas, such as those of the immortality of the soul, of transmigration and karma. The sacred book of the Sikhs is the Adi Granth or Granth Sahib (completed in 1604), of which the Japji section was written by Guru Nanak himself.

Islam :
Islam had its genesis outside India, in what is now Saudi Arabia. Followers of this faith are called Muslims. Islam was basically propounded by prophet Mohammad (born around 570A.D. in Mecca), although the belief is that it was brought to the world by Adam and different messengers were sent by God to preach this lesson and Mohammad was the one who came last. In other words, Mohammad gave the final form to an already existing religion. Muslims are also referred to as Mohammedans.