At a certain time, two demons, by name of Shumha and Nishumbha were born with the intention of conquering the earth and the Heaven (Swargalok) and rule them. Defeated by their might, Lord Indra, the king of Swargalok and all other deities started deserting Swarglok. These demons also perpetrated a reign of terror on the earth. At such difficult times, all together surrendered themselves to Mother Durga, who is the incarnation of Shakti (strength, energy of extremely high potential), and requested her to save them from this holocaust.
Acceding to their prayers, Mother Durga destroyed these two demons. At the very moment of her killing them, yet another demon, whose name was Raktabeej, struck Mother Durga. Another Raktabeej used to grow out of every drop of Raktabeej falling on the earth. To overcome this, Mother Durga assumed an extremely threatening tantric form and destroyed him. She was in such a rage on this occasion that in spite of several prayers and efforts, she could not be pacified. Thereafter, only after the gods and deities worshipped her in a special way (Divya Pooja) she was pacified and pleased and blessed the deities and the dwellers of the earth in several ways.
The night when this Pooja was performed is called ?Kalratri?. This night is the night of Deepawali. By worshipping Mata on the night of Deepawali, the worshipper gets unlimited strength, health, prosperity, and wealth. This Pooja results in very increased powers of concentration. The benefits of this Pooja are experienced by the worshipper immediately after the Pooja.