Sancte Michaël Archángele
defende nos in prœlio:
contra nequítiam et insídias diáboli
esto præsídium.
Imperet illi Deus,
súpplices deprecamur;
tuque, Princeps milítiæ cælestis,
sátanam aliósque spíritus malignos,
qui ad perditionem animarum
pervagantur in mundo,
divina virtute
in infernum detrude.
Amen.

The prayer to Saint Michael the Archangel is a short, powerful invocation that asks the heavenly warrior to protect us from the attacks of the devil. It is traditionally rendered in the form:

“St. Michael, the Archangel, defend us in battle. Be our protection against the wickedness and snares of the devil. May God rebuke him, we humbly pray; and do thou, O Prince of the heavenly host, by the power of God cast into hell Satan and all the evil spirits who prowl throughout the world seeking the ruin of souls. Amen.”

The prayer belongs to the ancient Christian tradition of invoking the archangel as a protector against evil. Its wording appears in the liturgical collections of the Catholic Church and has been used for centuries in public and private prayer. The prayer was already part of the Church’s liturgical life when Pope John Paul II recalled it in his 1987 address to the faithful of Monte Sant’Angelo, noting that it had been recited “at the end of the Holy Mass” as a communal appeal to the archangel. Its presence in the official exorcism and supplication rites of the Sacred Congregation for Divine Worship further attests to its longstanding use within the Church’s prayer‑books.

Liturgical Use

1. Mass – The prayer is traditionally said after the concluding prayer of the Mass, especially on feasts dedicated to Saint Michael (e.g., the Mass celebrated for the Gendarmerie Corps of Vatican City State in 2015 explicitly asked for “the grace to be defended by the Archangel Michael against the ‘snares’ of the devil”.
2. Exorcism rites – The Roman Ritual’s “De Exorcismis et Supplicationibus Quibusdam” includes the same invocation as part of the official exorcism formula, asking Michael to be “our preserver in the battle against the prince and powers of darkness”.
3. Litanies and private devotion – Contemporary liturgical booklets of the Catholic Bishops’ Conference of England and Wales repeat the prayer verbatim as a popular litanic invocation to Saint Michael.

Thus the prayer functions both as a communal liturgical element and as a private devotional appeal for spiritual protection.

Michael is invoked as “the Prince of the heavenly host,” the chief commander of the angels who fights the devil (cf. Revelation’s “war in heaven”). The prayer asks him to “defend us in battle,” echoing the Church’s belief that the archangel intercedes for the faithful against demonic attack.

In sum, the Saint Michael prayer is a concise, scripturally rooted appeal to the archangel’s protective power, originating in the Church’s ancient tradition, incorporated into the Mass, the rite of exorcism, and popular litanies, and conveying the faithful’s trust in divine assistance against the devil’s assaults.