Hinduism is exceptional among the world religions that it has no creator or date of beginning. While most key religions originate from new thoughts taught by a charismatic leader, Hinduism is considered to be simply the religion of the people of India, which has gradually evolved over thousands of years. The origins and authors of its sacrosanct texts are basically unknown.
Hinduism's ancestry dates back up to 2000 BC, which makes it obvious that it is one of the oldest surviving religions. Because of its great age, the early history of Hinduism is ambiguous. The most ancient writings are yet to be deciphered, so for the earliest periods scholars must rely on educated guesses based on archaeology and the study of contemporary texts.
The word Hindu was derived from the river Indus. The people of the Harappan civilization (also known as the Indus valley civilization) who lived near that river about 2500 BC carved images of several different Gods on their clay seals. Harappan writings could not be read and so it’s not certain what the Harappan people called their Gods. But some of these Gods look like the anon Hindu Gods Shiva and Vishnu, this may be painstaking to be the earliest part of Hinduism.
The first written evidence of Hinduism which we can read is the Rig Veda, a long epic in Sanskrit probably composed around 1000 BC. It is one among the four great Vedas. People sang or recited the Rig Veda for hundreds of years before it was written down as a book around 300 BC.
Around 300 BC, people began to worship new Gods, who didn’t like animal sacrifices. These new Gods were Vishnu and Shiva. Generally people gave Vishnu and Shiva flowers, food, prayers, or music, but they didn’t kill animals for them. They began to worship Vishnu and Shiva more, and paid less attention to their old Gods Indra and Varuna as the days passed.
Much later, between 400 and 650 AD, at the end of the Gupta period, another new god came into Hinduism. This new god was a Mother Goddess. Cows were sacred to this Mother Goddess, and so Hindus gradually stopped eating beef. The female Gods, known as Uma, Parvathi, Kali and Samundi came in to existence as people started giving shapes to their thoughts. And as centuries passed, even more Gods came into existence.
But still, the actual day of origin or the creator of this religion stays a mystery!