And were the Christians of their own time even celebrating the Messiah’s birthday?
So why did the Muslims not establish a celebration for the Messenger’s birthday the way the Christians celebrate the Messiah’s, except to avoid imitating them?
This alone proves that the Prophet’s birthday celebration is a newly-invented, reprehensible innovation. Added to that, as we have already pointed out, it is riddled with acts of major and minor shirk, involves spending wealth in disobedience to Allah, wastes time, and contains other evils besides.

Therefore it is incumbent upon the Muslims to take heed and confine themselves to what Allah has legislated, for in that lies all goodness and blessing and true happiness in this world and the Hereafter. Allah is the One who grants success.

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Celebrating birthdays

Question: In your view, what is the ruling of the Sacred Law on celebrating birthdays? Is it a good innovation or a bad one?

Answer: Celebrating birthdays—whether the birthdays of prophets, scholars, or ordinary people—is among the innovations for which Allah has sent down no authority. The greatest person ever born is the Messenger of Allah ﷺ, yet it has not been authentically reported from him, his rightly guided successors, his Companions, the generation that followed them, or any of the virtuous early generations that they ever held a celebration on the occasion of his birth.

This practice is nothing but a newly-invented innovation that emerged after the virtuous generations, at the hands of some ignorant people who imitated the Christians in their celebration of the Messiah’s birth.