Question: We have a man with us at work who approves of the celebration of the birthday (i.e. the Prophet?s (sal-Allaahu `alayhe wa sallam) birthday), and advocates and insists upon this. Should I abandon him for the Sake of Allaah or not? What should I do? ?and may Allaah reward you with good.
Response: Celebrating the Prophet?s birthday is an innovation, and whoever pursues this (path) is an innovator (mubtadi?) if he insists on doing so and does not accept the (sincere) advice, (rather, choosing to) continue in calling to (celebrating) the birthday and arousing interest in it. (In this case), then, it is obligatory to abandon him since he is an innovator, and it is not permissible to maintain companionship with an innovator.