Reasons why a Muslim must stay away from participating / celebrating with the kuffars;
• The lies against Allah (about begotten a son) – making reference to Prophet Isā (عليه السلام) as son of God (Allah).
• The dubious belief in holy Trinity (i.e three in one.
• The status of Pophet Isā (عليه السلام) as being God that is worthy to be worshipped.
• The lies that Prophet Isā (عليه السلام) was killed and crucified on the cross, and that woke up (resurrected) again after three days.
• No one will enter Paradise except he is either a Jew or Christian.
All these are false and clear misguidance. (As against what is explained in the Qur’ān and Sunnah).