Sacrilege is in general the violation or injurious treatment of a sacred object. In a less proper sense any transgression against the virtue of religion would be a sacrilege. It can come in the form of irreverence to sacred persons, places, and things.
Catholic Teaching
Many manuals on moral and sacramental theology likewise confirm that “Unworthy treatment of the Eucharist is the worst of sacrileges….”[8] “They who make a sacrilegious Communion,” writes St. Cyril, “receive satan and Jesus Christ into their hearts—satan, that they may let him rule, and Jesus Christ, that they may offer Him in sacrifice as a Victim to satan.”
Sacrilege is in general the violation or injurious treatment of a sacred object.
Personal sacrilege means to deal so irreverently with a sacred person that, whether by the injury inflicted or the defilement caused, there is a breach of the honour due to such person.
Sometimes the guilt of sacrilege may be incurred by omitting what is required for the proper administration of the sacraments or celebration of the sacrifice, as for example, if one were to say Mass without the sacred vestments.