Why is diwali celebrated?what is the cause of it?

Deepavali, or Diwali means "a row of lights". It falls on the last two days of the dark half of Kartik (October--November) The significance of Diwali is related to legends. The central theme of all legends point out to the classic truth of the victory of the good over the evils. According to Ramayana, Diwali commemorates the return of Ram, an incarnation of Lord Vishnu and the eldest son of King Dasharath of Ayodhya, from his 14-year exile with Sita and Lakshman after killing the Ravan, a demon king. The people of Ayodhya illuminated the kingdom with earthen diyas (oil lamps) and fireworks to celebrate the return of their king. This festival commemorates Lord Ram's return to his kingdom Ayodhya after completing his 14-year exile. Twinkling oil lamps or diyas light up every home and firework displays are common all across the country. This celebration took place on the night of the new moon of Ashwin (October-November). The tradition and the timing continued to be followed even these days. Though the four-day long festival centers round the new moon night, the night of lamps, each of the four days has an interesting story to tell of its own. The Day of Narakchaturdashi.This is actually the pre-Diwali day and the beginning of the four day long festival. The day is associated with the legend of the demon Naraka.This holy day marks the vanquishing of the demon Naraka by Lord Krishna and his wife Satyabhama. . This Narakachaturdashi day is dedicated to lights and prayers heralding a future full of joy and laughter. Day of Amavashya. Bali was the king of the nether world and his mighty power had become a threat to the gods. In order to curb his powers Lord Vishnu in the guise of a dwarf - a vaman - visited him and begged him to give him only that much land which he could cover with his three steps. Known for his philanthropy King Bali proudly granted him his wish. That very moment that dwarf transformed himself into the all-powerful Lord Vishnu. With his first step Lord Vishnu covered the entire heaven and with the second step the earth and asked Bali where to keep his third step. Bali offered his head. Putting his foot on his head Vishnu pushed him down to the underworld. At the same time for his generosity Lord Vishnu gave him the lamp of knowledge and allowed him to return to earth once a year to light millions of lamps to dispel the darkness and ignorance and spread the radiance of love and wisdom. Another version is that when Lord Vishnu in the guise of Vaman, sought three feet of land from the very generous king Bali Chakravarthy, Bali had to surrender his head as Vamana had conquered the earth and the sky in His two strides. Lord Vishnu banishes Bali into the nether world of Pathal by keeping his third stride on Bali's head. Later, pleased by his generosity, Lord Vishnu grants him a boon and he in turn requests the Lord to guard his palace at Patal Loka. Meanwhile, the Goddess Lakshmi, the consort of Lord Vishnu, is unable to bear the separation and her grief affects the functioning of the entire universe. Brahma and Lord Shiva offer themselves as guards and plead with Bali to relieve Vishnu. It is on this day of Amavasya Lord Vishnu returns to his abode and Goddess Lakshmi is delighted. That is the reason it is believed that those who worship Goddess Lakshmi on this day would be bestowed with all the riches. According to another version it was on this day Goddess Lakshmi emerged from Kshira Sagar when the Gods and demons were churning the sagara for Amrutha Bhandam. Padwa: The day following the Amavasya is "Kartik Shuddh Padwa" and it is only on this day that the King Bali would come out of Pathal Loka and rule Bhulok as per the boon given by Lord Vishnu. Hence, it is also known as "Bali Padyami". This day also marks the coronation of King Vikramaditya and Vikaram-Samvat was started from this Padwa day. Govardhan-Puja is also performed in the North on this day. As per Vishnu-Puran the people of Gokul used to celebrate a festival in honor of Lord Indra and worshipped him after the end of every monsoon season but one particular year the young Krishna stopped them from offering prayers to Lord Indra who in terrific anger sent a deluge to submerge Gokul. But Krishna saved his Gokul by lifting up the Govardhan mountain and holding it over the people as an umbrella. Govardhan is a small hillock in Braj, near Mathura and on this day of Diwali people of Punjab, Haryana, Uttar Pradesh and Bihar build cowdung hillocks, decorate them with flowers and then worship them.

Diwali, also called Deepavali, is a major Indian festival that is very significant in Hinduism, Sikhism, and Jainism. Known as the "Festival of Lights," it symbolises the victory of good over evil. Hindus celebrate Diwali to mark the time when Lord Rama achieved victory over Ravana.

Rama came back to auyodhia after 14 years in forests and 6th Guru Sri guru Hargobind Sahib ji left the Gwallier killa alongwith 52 kings

It is a celebration of victory of good over evil.