Diwali is celebrated because a Hindu god named Sri Rama returns to his kingdom
story:In the kingdom of ayodhya there is a king called dasharadha.he didn't have children.as he want a child to rule his kingdom he went to a sage called vashista maha muni.he had arranged putra kameshti yagam,which helps to give a birth to a baby.the king dasharatha had three wives named kousalya, sumitra, kaikeyi.after the completion of this yagam kousalya had given birth to Rama.sumitra given birth to lakshman and kshatrugna.And kaikeyi given birth to bharatha.In this rama is the avatar of lord Vishnu.and lakshman is the big snake in which lord Vishnu will sleep.All are well trained in bow and arrow.these four sons had grown up.the king dasharadha want to make rama as the ruler of ayodhya.But the maid servant of the kaikeyi called mandara didn't like the ruling of rama.So she told kaikeyi- you have a boon , so utilize it by sending rama 14 years vana vas(going to forest and living there) so as to make bharatha as the emperor of the kingkom.she asked the the king dasharadha.by listening this the king shocked,fainted and died.At the time of his death the sons were not in the kingdom.after coming rama went to vana vas along with the sita his wife and lakshman.sita is the lord lakshmi avatar ans lakshmi is Vishnu's wife.rama,sita and lakshmana went into forest.In theforest sita sees a golden deer and wished to play with that so rama and lakshmana went.In that time ravana a brahmin who is ruling lanka at present sri lanka came and kidnapped the sita.While going in the air ways a eagle sawed and tried to stop then ravana killed that eagle but she is still alive in a critical condition
when rama came he noticed that ther is no sita he searched very much near by,then he found a eagle it said that the sita was kidnapped by ravana he also told the direction and died.rama and lakshmana are searching sita.he met a vanar called hanuman and one more.the other person has a problem he told to rama.then rama came to a deal that i will help you you help me by providing soldiers in the search of my wife sita.the deal was agreed by the both.rama solved his problem.and he helped in search of sita.hanuman is the great devotee of rama.hanuman is the avatar of lord shiva.at last they went to sri lanka by walking on stones placed on indian ocean and defeated ravan.then 14 years had completed.sita lakshman and rama went back to ayodhya this day is celebrated as diwali.
