Islam and the Quran

Can we congratulate non-Muslims on their religious celebration days?

It is different that a Muslim congratulating the celebration days of non-Muslims himself and congratulating the non-Muslim neighbors or friends on their celebration days.

It is not permissible for a Muslim to celebrate the religious days of non-Muslims, such as Christmas, Easter, passover etc. On the other hand, it is not wrong for a Muslim to wish those days to bring goodness to his non-Muslim acquaintance. Congratulating them on these special days does not mean internalizing those days. This is considered as for setting up good relations with non-Muslims.

For further information, see:

Relations with Non-Muslims: