And they say, “The Most Merciful has taken [for Himself] a son.” You have done an atrocious thing! The heavens almost rupture therefrom, and the earth splits open, and the mountains collapse in devastation, that they attribute to the Most Merciful a son. And it is not appropriate for the Most Merciful, that He should take a son.
It is enough to say as a Muslim that it is not permissible for us to celebrate Christmas in any way shape or form with any of its symbols. From the perspective of our fundamental beliefs, Allah has neither beginning, nor end. He does not give birth, neither was he born, nor is anything comparable to him.