The deliberate violation of sacred things. Sacred things are persons, places, and objects set aside publicly and by the Church's authority for the worship of God. The violation implies that a sacred thing is desecrated precisely in its sacred character. It is a sin against the virtue of religion.
Personal sacrilege is committed by laying violent hands on clerics or religious of either sex; by unlawfully citing them before secular courts, i.e., without just cause and without express permission of their ecclesiastical superiors; by unlawfully demanding of them the payment of civil taxes or military service; and by the commission of acts of unchastity by or with a person bound by the public vow of chastity.
Sacred places are violated by sacrilege through defilement, e.g., serious and unjust shedding of blood, as in willful homicide or by putting the sacred place (church or shrine) to unseemly use, e.g., secular trading, acts of debauchery; by grave theft from the Church or consecrated edifice; and by violating the immunity of a place as having the right of sanctuary.
Sacred objects are desecrated by sacrilege whenever something sacred is used for an unworthy purpose. This includes the Mass and the sacraments, along with sacramentals; sacred vessels and church furnishings; and ecclesiastical property. Desecration in each of these areas includes the deliberate invalid reception of the sacraments, simulation of Mass, grave irreverence to the Eucharist; gravely profane use of sacred vessels or vestments; and the unlawful seizure of sacred things or ecclesiastical property.
Sacrilege is many times reprobated in Sacred Scripture, notably in the second book of Maccabees and in the writings of St. Paul. Grave sacrilege in the Old Testament was punishable by death, and in the Catholic Church is considered a mortal sin. (Etym. Latin sacrilegium, the robbing of a temple, the stealing of sacred things.)