Mitra was an early Hindu god. He represented the sun, and had many similarities to other contemporary gods in nearby civilizations. Mitra was also notably the god of the oath, along with his associate, Varuna. Mitra, along with Varuna, was generally classed as an asura early on in Hinduism. Asuras are often referred to as demons, but it is important to note that the asuras were not necessarily evil, they were just formed in opposition to the gods known as devas. Perhaps the best comparison is found within the Greek pantheon, where gods such as Zeus and Dionysus were placed in opposition to titans such as Prometheus, not all of whom were necessarily evil.
There was an ancient deity, from the Proto-Indo-Iranian cultures, also named Mitra, who was a god of oaths. This god gave rise to the Mithra god of Zoroastrianism, as well as Mithras from the Greco-Roman period. He also became the Hindu Mitra in early Hinduism.
Mitra is one of the oldest extant gods of Hinduism, and a record of him appears as far back as the 15th century BCE, when he was invoked as a watcher over a pact made between the Hittites and the Hurrians. Like Varuna, Mitra watched over the order of the entire universe, making things were as they were meant to be. Initially, Varuna and Mitra were presented as twins, and they would always appear together in defense of truth and honor. While Varuna watched over the movement of the spheres, Mitra was said to make sure dawn occurred, keeping the balance between light and darkness.
In many instances, Mitra and Varuna are actually combined into one being, Mitra-Varuna. In other cases the differences between the two are highlighted. Varuna is sometimes said to be as the monarchy, while Mitra is looked on as the priesthood, two vessels of power balancing one another equally to ensure the universe functions smoothly. As time went on, however, Mitra’s role diminished and Varuna became the more important god.
Mitra remained a popular god, however, and is sometimes invoked when signing a contract. Mitra is also the god of friendship, as it is the integrity of truth and oaths that keeps a friendship strong. In many myths Mitra is viewed as a sort of go-between for man with the gods, helping to negotiate with them.
One of the most important prayers in the Rig Veda is written in gratitude to Mitra, and acknowledging the seeking of perfection. The prayer, the upasthaana, is addressed to the god-head in praise of the sun. The upasthaana reads roughly: Oh God! In search of you we leave behind the eternal physical realm, to meditate on an even greater entity, our soul. We attain to the most blissful, luminous light, the illuminator of all things, even of the shining glory of the sun, who is the greatest of all. All the things of this world act as signals to lead us to the god-head, the knower of all things, the possessor of all destructive and sustaining powers. Surely that is the correct path to understanding this universe.