It is not permissible for a Muslim to eat things that the Jews and Christians make on their festivals, or what they give him as a gift on their festivals, because that is cooperating with them and joining in with them in this evil, as is explained in question no. 12666.
It is not permissible for him to congratulate them on their festivals in any way whatsoever, because that implies approval of their festival and not denouncing them, and helping them to manifest their symbols and propagate their innovation, and sharing their happiness during their festivals, which are innovated festivals that are connected to false beliefs that are not approved of in Islam. See also question no. 47322.
And Allaah knows best.