Vishnu (or Visnu) is one of three great gods in Hinduism, being one of the Trimuti, the others being Brahma and Shiva. Vishnu antecedents are among the Dravidian people in the pre-Aryan past of India, and his current stature is based on the amalgamation of many traditions. Vishnu was more easily absorbed in the Vedic Aryan pantheon more easily than Shiva since there are indications of Vashnu’s various forms in the earliest Upanishads (possibly in insertion as late as 600 BC), but the fullness of this deity does not appear until the following centuries. It is in the Mahabharata, the Bhagavad-Gita, and the Puranaswhere Vishnu assumes his final form and the doctrine of the avatar is completely stated.
Vishnu appears as a majestic figure, a Godhead at peace, propitious anthropomorphic. A solar and cosmic deity, he is god of the ocean and luminous sky, the protector and sustainer of the world. He is known as the All-Provider, being the cohesive, centripetal constructive power of the universe, as opposed to the dark, dispersive, destructive power of Shiva. The origin of Vishnu’s name is uncertain, some speculation suggests that the roots signify a pervading or entering power, others indicate or a phallic god. Whatever the source, he is seen as a universal intellect, the cosmic vision, the inner cause by which things exist, the symbol of eternal life binding the universe together.
In Hindu mythology Vishnu is usually depicted as a young handsome youth of a dark blue color, and dressed like an ancient king. He holds a conch shell in his four hands, also a discus, a club and a lotus flower. His vehicle is Garuda, the sun bird, enemy of all serpents. This antagonism is dramatically played out in Krishna’s defeat of the water serpent Kaliya. Reminded of his divine nature by Balarama, Vishnu, lying as Krishna at the bottom of a pool bestirs himself and dances upon the threatening Kaliya’s head. Sparing the exhausted serpent king, Krishna said: “You shall no longer reside in the Yamuna River, but in the vastness of the ocean. Go! Moreover, I tell you that Garuda, the golden sun bird, deadly foe of all serpents and my vehicle through infinities of space, forever shall spare you, whom I have touched.” It is suggested that this popular legend recounts the supplanting of the local nature divinity by an anthropomorphic god. A parallel may be seen in Greek myth when Apollo conquers the earthbound serpent of Delphi, who oracle he arrogated to himself after killing the python.
Presently Krishna is considered the last chief avatar that precedes Vishnu, although there were others, half have been human and half animal. Whereas Vishnu was the exponent of loftier events, Krishna is the most popular deity in India today because human characteristics are seen in him, and also human weaknesses.
Why is Vishnu so important
Vishnu, Brahma and Shiva are the most important gods in Hinduism.
Rice, Edward, Eastern Definitions: A Short Encyclopedia of Religions of the Orient, Garden City, New York, Doubleday, 1978, pp. 395-398
Cotterell, Arthur, A Dictionary of World Mythology, New York, G. P. Putman’s Sons, 1980, pp. 84-88