The Hindus and the Muslims are extremely different religions. Indian and Pakistani Muslims do not believe in castes, and are considered unclean and more than slightly crazy by Hindus. Hindus worship a seemingly infinite number of deities, have a rigid caste system and are strange idolators by the Muslims. They have different alphabets and agree on nothing other than the world would be better if the other groups would just vanish.
If God had anything to do with establishing either of these religions knowing that the other would have to share real estate with it, he has a very strange sense of humor: if he devised both of them, it is certain that the discordians were clearly right: God is an insane woman.