"The Witness of the Disciples," the Rev. Randy Weber, preaching. This service includes the sacrament of communion and Tenebrae: The Service of Shadows. Early Christian churches had beautiful and dramatic services to commemorate the events of Holy Week; they called one of these services Tenebrae—a Latin word meaning “shadows” or “darkness.” The distinctive feature of a Tenebrae service is the gradual extinction of lights in the Sanctuary.