Some also believe that the festival of diwali originated from the event of Samudra manthan, the churning of the ocean to retrieve Amrita, tha magic potion. Below is the detail of the event and the view:
Once, in ancient times, the asuras (the evil ones) became very strong, while the devas (Gods) remained weak. Concerned for the balance of power, Lord Indra, the King of Devas, asked for help from the lord Vishnu.
Indra explained the lack of power of the devas, and the havoc the asuras are playing with them. He sought his help to restore the balance of power, or to help make the devas more powerful.
Lord Vishnu smiled as the devas, and informed them that there is only one solution to their problem. They will need to consume Amrita, the magic potion. It can be found only deep in a cavern, under the bottomless ocean, buried in a golden pot filled with amrita- the elixir of immortality. Those who drink of it will gain great strength and immortality.
"How do we raise it?" asked the bewildered devas.
"By churning the ocean, of course," replied Vishnu.
“And how do we do that?”
“You will need to take the biggest mountain, and use Basuki, the biggest serpent, as the rope. Then you will need to churn the sea with the mountain to get the Amrita out.”
"But we are not strong enough," lamented the devas “besides, the serpent needs to be pulled by both sides”
"Then you must ask the asuras to help you," said Vishnu.
"Then, they will also ask for a share of the potion, and they will be immortal too?" asked the devas.
"I will make sure they do not get any," assured Vishnu, with a mischievous twinkle in his eyes.
Indra and his delegation then approached Lord Bali, the King of Asuras. They told him about the pot of amrita at the bottom of the ocean.
"Only if we work together we can get our hands at that magic pot," they exclaimed. "We need your help."
The lure of immortality finally made Bali and his asuras agreed to help them-as long as they received their fair share of the potion. Peace was declared, and devas and asuras set off to churn the bottomless ocean together.
It was the fifteenth day of the bright half of the month of Kartika, the night of the new moon. The Sun was at his lowest point on the horizon, and the moon was but a slice in the sky. The night loomed dark and long.
Using the highest mountain as a pole, and the longest serpent Basuki as a rope, devas and asuras began churning the ocean. They churned with great gusto and as they churned fish, sharks, and even the whales in the ocean were tossed up and down. last, from out of the waters, surfaced a smoldering cauldron of vile blue liquid. It was the strongest poison of the universe called Holahol.
Now the problem was what to do with the poison, as letting it off would poison the whole Earth.
At that time Lord Shiva came to the rescue. He took the poison and stored it in His throat. But such was the power of the poison, that it stained Shiva’s throat blue, and from thereon, He acquired the name “Nilkantha” The Blue throated one.
A tiny drop of poison fell to the ground and was lapped up by snakes, scorpions, and other creepy-crawly creatures that have venomous fangs.
The asuras and devas then returned to their task and began churning the ocean once more. Again, they churned with great gusto and as they churned the ocean swirled and swished, tossing the fish, sharks, and even the whales of the ocean up and down.
At last, from out of the water emerged a pink lotus, upon which sat a radiant devi, a goddess. Dressed in silks of green and gold, jewels gleaming at her neck and wrists, she held a garland of fragrant flowers in her hands. Gold coins fell from her palms and her anklets tinkled as she moved.
Indra hurried to fetch a throne for her to sit upon and Bali brought a parasol to shield her. Rivers swelled in their banks, cows yielded more milk, and Mother Earth brought forth a bountiful harvest that year.
With a sweet smile hovering on her lips, the devi looked around shyly for a husband. Spotting the great god Vishnu, so strong and handsome, she placed the garland around his neck. Thus, married to Vishnu, she became Lakshmi, the Goddess of Prosperity.
People came to worship the goddess and seek her blessings for the coming year. They lit lamps to brighten the dark night and distributed sweets and other delicacies. There was much feasting and rejoicing. The devas and asuras returned to their task of churning the ocean once more. They churned with great gusto and as they churned, the oceans swirled and swished, tossing fish, sharks, and even the whales of the ocean up and down.
At last, from out of the waters emerged a radiant being bearing a golden pot. "I am Dattatreya, the Lord of Good Health and Medicine," he announced. "Here is the amrita that you seek. Those who drink it will gain strength and immortality."
There was a great cheer as the devas and asuras realized that their task was over. Both Lords Indra and Bali stepped forward to take the pot.
"As it was our idea, we will drink of it first," said Indra, tugging it to the right.
"Without us, you would not have had the strength to churn the ocean," retorted Bali, tugging it to the left. "Give it to us first."
And so it went, back and forth, right and left. Tempers flared and it almost came to blows, when suddenly! ...
Suddenly, from out of nowhere, appeared a beautiful maiden such as they had never seen! Her dark eyes were like blue lotuses and her air of mystery enchanted devas and asuras alike. It was Lord Vishnu, who took the form of a lovely girl, to divert the attention of the asuras.
Smiling sweetly and coyly, she took the pot from them. "Silly men, why quarrel over this?" she scolded playfully. "Sit down and I will serve it equally amongst you."
Meekly they sat down, devas facing north and asuras facing south, as the beautiful maiden danced between them. Flirting outrageously with the asuras, she distracted them while she slyly served the amrita to the devas. Soon, all the devas had received the magic potion and there was not a drop left for the asuras.
The beautiful maiden then threw down the pot and, laughing scornfully, vanished as suddenly as she had appeared.
The spell was broken and the asuras realized that they had been tricked! There was no potion left for them.
But one asura, realizing that they were being tricked, had sat down amongst the devas, assuming the form of a deva. He was just about to drink the potion after taking it in his mouth, when lord Vishnu spotted him. He immediately used his charka to behead him. However, as his head portion had already received the portion, it became immortal. Vishnu threw him up at the space, where he still tries to gulp the moon and the sun from time to time, the reason why we have the solar and lunar eclipses. But since he does not have a body, the sun and the moon comes out from his throat, and the eclipse ends.
The asuras rushed for their weapons and peace was ended. But, having drunk the potion of immortality, the devas were now an even match for the asuras and the balance of power was restored.
However, to this day, Hindus celebrate the birth of the goddess Lakshmi from the bottomless ocean, and her marriage to Vishnu, on this darkest night of the year, by lighting Deepavali row of lights. And, according to some, this is how Deepavali, the festival of lights, came into practice.
On the next day, they worship Lakshmi, the Goddess of Wealth and Prosperity, to seek her blessings for the coming year. Some also worship the golden Dattatreya, the Lord of Medicine, for bringing forth the pot of amrita, and pray for good health and a long life.