Demon
The contemporary Roman Catholic Church unequivocally teaches that angels and demons are real beings rather than just symbolic devices. The Catholic Church has a cadre of officially sanctioned exorcists which perform many exorcisms each year. The exorcists of the Catholic Church teach that demons attack humans continually but that afflicted persons can be effectively healed and protected either by the formal rite of exorcism, authorized to be performed only by bishops and those they designate, or by prayers of deliverance, which any Christian can offer for themselves or others.
Unclean spirit
Such exorcisms are performed rarely by the 21st-century Western church; the more common exorcism involves the ritual preparation of holy water ("aquae"). The 9th-century Stowe Missal preserves an early Celtic formula as "procul ergo hinc, iubente te, domine, omnis spiritus immundus abscedat" ("Therefore at your bidding, Lord, let every unclean spirit depart far from here"). In a Latin version of "The Blessing of the Waters on the Eve of Epiphany" performed in Rome and recorded at the turn of the 19th–20th centuries, the unclean spirit is commanded "per Deum vivum" ("by the Living God"). The modern Latin rite to exorcize holy water banishes any "pestilent spirit" ("spiritus pestilens") or "corrupting atmosphere" ("corrumpens aura"); see Rituals and uses of holy water.