Christmas, the festival of the “birthday of the Lord” (Latin: nativitatis Domini, natalis Domini), has been celebrated on December 25 since 354, probably in order to suppress the birthday festival of the pagan god Sol Invictus (the Unconquered Sun). The Christmas liturgy is informed by thanksgiving for the birth of Jesus Christ and the associated Christian hope for redemption. The English designation as “the mass of Christ” is attested since late Middle English (Christes mæsse). The German word W…