Is it permissible to congratulate Christians on their holidays, to compete with them in matters of creed, to consider them like Muslims in their belief in the validity of their religion, to prefer them over some Muslims, and to frequently associate with and love them?

It is not permissible to congratulate disbelievers on their holidays and religious rituals, as this involves participating with them and affirming their falsehood. However, congratulating them on matters not specific to their religion, such as marriage, birth, and good health, is not forbidden.