Allah Ta’aala has mentioned clearly in the Holy Qur’aan:
For you your religion and for us is our religion.
(We will not compromise our Deen in order to please the Kuffar no matter how close they may be to us.)
Nabi Sallallahu Alaihi Wa Sallam said: Whoever resembles any nation will be regarded as part of them. It is also mentioned in the Hadeeth that a time will come when people will be prepared to sell their Imaan for a few coppers of this world.
In the light of the above mentioned verse and Ahaadeeth, we should seriously reconsider our taking part in the Hindu celebration; be it in the form of wishing them a happy diwali, bursting fireworks, SELLING fireworks, eating their prayer food, etc.
This will result in earning the curse of Allah Ta’ala and could eventually lead a person out of the fold of ISLAM (May Allah protect).
It is mentioned regarding a pious person that someone saw him in a dream wherein he was well except that his tongue was wrapped in a snake. The person asked him the reason for him being punished.
He said: On the occasion of the color celebration of the Hindus, I saw a donkey that was not colored. I was chewing paan (betel leaf) and I spat the reddened spit on that donkey not thinking much of it.
However, this is the punishment of that action of mine.
May Allah Ta’ala protect us from taking part in any of the Kuffaar customs and selling our Deen for the Dunya.