Hinduism came into importance about 2000 B.C. when the Aryans conquered the people of the Indus Valley. The Aryans brought their religions with them. It was a religion of hymns, prayers, and chants which, in time, were written down in what is now called Vedic literature. The Vedas are thought to be 'revealed wisdom' and are as sacred to the Hindu as the Bible is to the Christian.
Many gods populate the pages of the Vedas. These remind us of the gods and goddesses of Greek and Roman mythology. Like many other ancient people, the Aryans believed that these gods could cause death and disaster, so the object of their religion was to keep the gods happy.
Out of the Hindu system came a group called the Brahmans who performed the duties of priests. The Brahmans grew more and more powerful until they became the highest social class. They added more writings to the Vedas that they called the Brahmanas. They describe elaborate sacrificial rituals.
Around 500 B.C., still more writings were added to the Vedas. Their purpose was to establish a rigid class system. One hymn tells how four classes of people came from the head, arms, thighs and feet of the creator god, Brahma. The four classes are Brahman, or priest; Kshatriya, or warrior and nobleman; Vaisya, or peasant; and Sudra, or slave. The first three classes can take full advantage of all the Hindu religion has to offer, but the Sudras are not even allowed to hear the Vedas or to use them to try to find salvation.