The Hindu faith has been a speculated to be 10,000 years old based on recent Brahmin prayer recordings.

Linguists were able to take the different prayers back through the different languages some originated in.

If I recall correctly, they were some prayers that could not be translated until anthologist walked by. Turns out, they were animal sounds and it's thought that the religion started from father's teaching sons about the animals that were found locally and then they began to be worshiped and the calls for the animals were the foundations of those prayers.