Although Diwali is majorly celebrated by Hindus there are several other religions who give equal importance to Diwali. In a diverse country like India different religion and states have different ways of celebrating Diwali.
There are different beliefs and reasons behind its celebration but the joy that the festival brings is the same. It is not important to be of a particular religion or faith or nationality to celebrate this festival.
For Hindus it is a festival which symbolizes the success of morality over evil. For Jains, it is a day when nirvana was attained by the Lord Mahavira who is last Jain
Tirthankaras whereas for Sikhs Diwali is related to the freedom struggle. While Guru Nanak was fasting, a king tried to feed him meat, he refused to consume it.
People protested against this and were gathered outside the palace with lanterns, candles and torches.
Soon the Guru was released by the king and this is the reason why Diwali is celebrated by the Sikhs.