Celebrating Christmas is not enough evidence to declare a Muslim non-Muslim
21-3-2010 | IslamWeb
Question:
Assalamu alaikum. Dear sheikh. Is the muslim that celebrates christmas a kafir? Please keep in mind that when he is asked he says that he is only celebrating the birthday of Isa and he celebrates only with his family (in his house) not with any christians. Is this person a kafir or just a bidai? Some brothers discussed this and one said he was a kafir while the other said he was not but he was a sinner. Please give us an answer with elaboration when this person is a kafir and when he is not a kaffir but just a fasiq! Jazakumullahu khayran.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad 
is His slave and Messenger.
First of all, it should be noted that it is forbidden for a Muslim to celebrate Christmas and we clarified this in Fataawa 83628 and 86876.
However, a Muslim does not become a Kaafir (disbeliever) just because of celebrating Christmas, but by doing so, he commits a forbidden matter and becomes a dissolute Muslim who is obliged to repent.
If, in addition to this celebration, he said any of the statements of disbelief of the Christians or did any acts of disbelief, like wearing the cross and the like, then he has indeed done an act that takes a person out of the fold of Islam but he is not ruled to be as such unless the evidence is clarified to him and then if he insists on it after the matter is clarified to him, he would be ruled as a non-Muslim.
A question was asked to the Permanent Committee of Fatwa in Saudi Arabia and it reads: “We differed in regard to a Muslim who wears the cross which is a slogan of the Christians and some of us ruled that he is a non-Muslim without discussing the matter, and some of us said: “We will not rule that he is a non-Muslim until we discuss the matter with him and clarify to him that this is forbidden, and that it is a slogan of the Christians, and then if he insists on wearing it, we would rule that he is a non-Muslim.”
The answer of the Committee came as follows:
“All praise be to Allaah and may Allaah exalt the mention of the Prophet Muhammad () his family and his companions, to proceed:
It is an obligation to give details on this matter and the matters that are similar to it; if the ruling of wearing a cross is clarified to him, that it is the slogan of the Christians and that wearing it is evidence of being affiliated to them and being pleased on what they are upon, and then he insists on wearing it, then it is ruled that he is a non-Muslim as Allaah Says (what means): {O you who have believed, do not take the Jews and the Christians as allies (friends, protectors, helpers). They are [in fact] allies of one another. And whoever is an ally to them among you — then indeed, he is [one] of them. Indeed, Allaah guides not the wrongdoing people.}[Quran 5:51] The word wrongdoing in the verse refers to greater Shirk that takes a person out of the fold of Islam. Also, it [wearing a cross] is showing that one agrees with the Christians in their claim that ‘Eesa (Jesus) 
was killed while Allaah denied this in His Book as Allaah Says (what means): {…but they killed him not, nor crucified him, but the resemblance of 'Eesa (Jesus) was put over another man (and they killed that man).}[Quran 4:157].” End of quote.
Finally, it should be noted that declaring someone as a Kaafir (non-Muslim) is very serious, and a Muslim should not hasten to do so unless it becomes clear to him that the conditions for declaring someone as such are met and the impediments for declaring him as such are removed.
For more benefit, please refer to Fataawa 84943 and 91677.
Allaah Knows best.