As per mythology, Lord Rama invokes Goddess Durga and chants the Chandi describing the supreme power and the creation of Goddess Durga to fight the asuras or Demons. It also describes the majestic battle between Goddess Durga and the demon king Mahishasura. Mahishasura has been tormenting the Gods. Gods then appealed to the trinity of Brahma, Vishnu and Maheshwara . They all came together to create a powerful female form with 10 arms-Maa Durga or Mahamaya, the Mother of the Universe, who embodies the primeval source of all power. The trinity then bestowed upon this supreme creation their individual power which are symbolized by different weapons in the hands of Goddess Durga. Armed like a warrior, the Goddess rides a lion to battle with the Mahishasura . After a fierce combat, Mother Goddess who is also called Durgatinashini or Mahishamardini is able to slay the Asura King with her trident. Heaven and earth sighed with relief. Peace and Prosperity was again regained in the earth.
Durga pooja is the most important celebration for Hindu, Bengalis and in Eastern India in general. It is now celebrated by Bengalis all over India and outside India also.
The worship of goddess Durga during this autumn Navaratri has its origin in Lord Ram’s worship of Goddess Durga before his battle with Ravana. During the first 7 days Devi is invoked to appear in all her glory. On the 8th day Goddess Durga slays Mahishasura. On the 9th day the pooja is known as Sandhi pooja like declaration of ceasefire in today’s war. On the 10th day , it is victory celebration in the battle between the good symbolized by God and the evil symbolized by the demon or Vijoya Dashami.
According to Vedic mythology, a celestial demon known as Swarnabhanu undertook a severe penance invoking Lord Brahma, the creator among the trinity. Brahma pleased with his penance granted him the status of the planet. In a later time both Gods and Demons were involved in churning of the celestial ocean to extract the Divine Nectar or Amrita. At the end of this churning exercise Dhanvantari , the celestial physician, came out with a pot containing Amrita. The pact was that both Gods and demons will share equally the Divine nectar. The nectar would give immortality. The demons rushed to partake the Amrita and because of their greater physical power, the Gods were left behind. The Gods requested Lord Vishnu for help. Vishnu himself did not want the demons to partake the divine nectar, as that would mean the evil forces will gain permanence,leaving little chances for goodness to prevail in the world.