Hinduism is not a revealed religion like Christianity or Islam. There was no First Prophet. It is a loosely knit pattern of ideological faith having its roots in Dharma and Satya. It is a sociological and ethical pattern of life that goes by the name of Hinduism.
Through centuries, it has undergone a variety of changes. In ancient India, fundamental truths were taught with the help of myths and fables. As time passed, the truths were forgotten, myths and fables remained. Many a reformer has tried to restore Hinduism to its pristine glory, but the outcome, for all practical purposes, has been very short – lived. It has not reached the common masses and, therefore left no imprint on their faith. The ingrained habit of the philosopher in India to consider and identify his philosophic goals with those of the religious ideals has led the common man to shun any religious thinking on the ground that it is beyond his reach. The common man has so far found satisfaction in conformities to the externalities of the religion.
According to Baba Sahib Ambedkar, the Chief Architect of the Indian Constitution, a Hindu fails to define what is Hinduism and what makes him a Hindu. A man claiming himself to be a Hindu can always go to a Church/Masjid/Gurudwara, perform worship along with the devotees there and still call himself a Hindu.
Then, what do we call the specific way of life that is being led by those Indians who are not Muslims/Christians/Buddhists/Sikhs/Zoroastrians etc? We call it as “The Vedantic Religion”. That means the religion based on Vedanta Ideology. (Vedanta is the collection of books like the Vedas, Upanishads, Brahmanas, Aranyakas etc.)