Q: I would like to find out if it is okay to send out seasons greetings to customers and suppliers? Would it be wrong to say Merry Christmas and Happy New Year or should one try to rather just say happy holidays? Overall is it a sin to wish a person on their religious holiday eg. Happy diwali etc?
A: Allah Taala says in the Quraan that one should not assist in sin. By greeting them with such greetings gives credence to their religious festivities. Thus one should not greet them with merry Christmas etc. One should rather use happy holidays.