Story of Kurma Avtar
There was a remarkable story related with Gods (Devatas) and Demons (asuras) belonged from ancient times. Day by day there was battle between Devtas and Asuras . All of a sudden gods were going to loose their strength due to the extreme curse that was given by Saint Durvasa who was short tempered by nature.
Story behind this curse that once Saint Durvasa offered the garlands of beautiful flowers to Lord Indra-the king of Gods. But proudly he passed it to his elephants carelessly trampled that all.
Then to get the rid from this all Gods (Devas) came to Trinity-Brahma-Vishnu-Mahesh and prayed to come them out from this situation. They suggested them to churn the ocean of milk and get the Nectar of immortality. But this was impossible for only God therefore Lord advised them to fulfill it by Demons’ help.
Gods asked Demons to help in lifting the mountain. They decided to share equal nectar of immortality that would be created by churning. They used Mt Mandara for churning stick and serpent Vasuki as the rope, wrapped it around the mountain and started to churn the ocean.
At the starting, Indra who was king of the gods, played a Machiavellian trick, asked the demons (asuras) for the head end of vasuki. But demons (asuras) expecting foul play, obtained the head end, only to be tricked as the poison from Vasuki was slowly weakening them.
Both sides would hold an end of the snake (serpent) and alternately pull on it, causing the mountain to spin (rotate), by which the Ocean could be churned . But churning the mountain was proceeding and then slowly begun to sink and then Lord Vishnu emerged in the form of the KURMA (turtle) and supported the mountain afloat.
As the ocean was going to be churned, a deadly poison (Halahala) came out that can be threatened to chock all human and other living things. Then Lord Shiva drank this whole poison and held in his throat and causes of this his throat’s color turned into blue so he called as “Neelkanth Mahadev”.
The same way Kamdhenu (Cow), Noble Horse named Shrava, Elephant named Aairavat, KalpaVruksh (tree), Apsaras, Bhagwati Laxmi, Varuni, Dhanush (Bow), Chand (Moon), Shankh (Conch), and last Dhanavantri emerged with a pot that containing the nectar.
As soon as Lord Dhanavantri came with the pot of nectar (amrita), the nectar of immortality was slowly out; the all demons rushed and grabbed it. All Gods were scared and appealed to Lord Vishnu who was in a form of KURMA. Then Lord Vishnu changed his form of a maiden-a beautiful apsara named “Mohini” and seduced the all demons (asuras) and asked them to allow her to distribute the nectar one by one and also to abide by her order of distribution.
As soon as the all Gods (devatas) were served the maiden (apsara) Mohini disappeared thus she totally deceived the demons (asuras) and made them totally weak.
This way Lord Vishnu made all gods immortal and helped in creating the Universe by giving support of his back through this KURMA avatar.