Referred to as Hindus in modern times, Sanatan is the oldest religion. The traces of its origin are not available anywhere but when we look into the scriptures, it starts even before the creation of the world. Lord Brahma is regarded as creator of the world, who not only created planet earth but also each and every single thing herein.
Unlike other religions, Hindu scriptures do not talk about non-hindus, basically indicating that there was none to be referred to. So it is not actually a religion but a way of life.
This religion has unique feature of flexibility for its followers. The Gods of this religion lay down different paths for everyone to follow so their is no lack of choice and you’re basically not restricted to do anything and live anyway you want. The only instruction is not not cause harm and prejudice to others.