The existence of the spiritual, non-corporeal beings that Sacred Scripture usually calls “angels” is a truth of faith. The witness of Scripture is as clear as the unanimity of Tradition. Who are they? St. Augustine says: “‘Angel’ is the name of their office, not of their nature. If you seek the name of their nature, it is ‘spirit;’ if you seek the name of their office, it is ‘angel:’ from what they are, ‘spirit,’ from what they do, ‘angel’” (St. Augustine, En. inPs. 103, 1, 15 : PL 37, 1348). With their whole beings the angels are servants and messengers of God. Because they “always behold the face of my Father who is in heaven” they are the “mighty ones who do his word, hearkening to the voice of his word” (Mt 18:10; Ps 103:20). As purely spiritual creatures angels have intelligence and will: they are personal and immortal creatures, surpassing in perfection all visible creatures, as the splendour of their glory bears witness. ~Catechism of the Catholic Church #328–330

Michaelmas is the celebration of the feast of St. Michael. Roman Catholics have been celebrating the valiant archangel since at least the fifth century. The Leonine Sacramentary (the oldest surviving liturgical text in the Church) mentions that a basilica built along the famous Via Salaria near Rome was consecrated to the Archangels on September 30. The Gelasian Sacramentary and Gregorian Sacramentary, written in the following 200 years, clarify that this was a celebration of St. Michael, and that the accurate anniversary of the basilica’s consecration was September 29. (Sometimes record keeping isn’t an exact science!)

In any case, September 29 seems to have been when people actually observed the holiday. And while that basilica is now lost to time—it survives only as a somewhat unimpressive archaeological site in the Castel Giubileo suburb of Rome—the legacy of this important feast remains.

One of the three Archangels venerated by name in the Catholic Church, St. Michael is an important figure and an exceptional ally in the fight against the Devil. Michael is mentioned five times in the Bible, taking the role of a protector of Israel, a guardian of the dead, and, in Revelation, as the angel who defeated Satan and cast him from heaven.

This storied bit of celestial combat has earned St. Michael the role of patrons to others who deal in deadly scenarios, including paramedics, mariners, fisherman, paratroopers, police officers, and military personnel. He is also the patron of grocers, owing perhaps to his feast day’s connection with harvest time.

In addition to the famous “Prayer to St. Michael” authored by Pope Leo XIII (and a favorite of Pope John Paul II), there are a number of prayers and hymns seeking the archangel’s aid, including a Chaplet of Saint Michael, written by a Portuguese Carmelite nun called Antónia d'Astónaco following a private revelation from the Archangel himself.

Catholicism is a remarkably physical religion. We recognize a God Who became fully man. We encounter God’s grace in tangible ways in each of the seven sacraments. We acknowledge that physical reminders—icons, rosary beads, sacred music—are powerful tools to help draw our minds and hearts to spiritual realities.

The very architecture of our abbey church is built with physical reminders that draw us into the mysteries of our faith. A great example is the rose window, which is positioned in the church such that every Michaelmas, September 29, the light from the sun will pass through the rose window and rest directly on the high altar. (Plenty of churches in Europe feature this kind of “solar geometry,” but with the exception of many of the California Missions this ancient approach to construction is quite rare in the US.) This is a small but significant reminder of the intense power and grace found at each and every Mass when God, fully present in the Eucharist, descends onto the altar. It is an illustration of the unity of heaven and earth that occurred during the Incarnation and has occurred at every Mass since!

The word "angel" denotes a function rather than a nature

You should be aware that the word “angel” denotes a function rather than a nature. Those holy spirits of heaven have indeed always been spirits. They can only be called angels when they deliver some message. Moreover, those who deliver messages of lesser importance are called angels; and those who proclaim messages of supreme importance are called archangels. And so it was that not merely an angel but the archangel Gabriel was sent to the Virgin Mary. It was only fitting that the highest angel should come to announce the greatest of all messages.

Some angels are given proper names to denote the service they are empowered to perform. In that holy city, where perfect knowledge flows from the vision of almighty God, those who have no names may easily be known. But personal names are assigned to some, not because they could not be known without them, but rather to denote their ministry when they came among us. Thus, Michael means “Who is like God”; Gabriel is “The Strength of God”; and Raphael is “God’s Remedy.”

Whenever some act of wondrous power must be performed, Michael is sent, so that his action and his name may make it clear that no one can do what God does by his superior power. So also our ancient foe desired in his pride to be like God, saying: I will ascend into heaven; I will exalt my throne above the stars of heaven; I will be like the Most High. He will be allowed to remain in power until the end of the world when he will be destroyed in the final punishment. Then, he will fight with the archangel Michael, as we are told by John: A battle was fought with Michael the archangel.

So too Gabriel, who is called God’s strength, was sent to Mary. He came to announce the One who appeared as a humble man to quell the cosmic powers. Thus God’s strength announced the coming of the Lord of the heavenly powers, mighty in battle. Raphael means, as I have said, God’s remedy, for when he touched Tobit’s eyes in order to cure him, he banished the darkness of his blindness. Thus, since he is to heal, he is rightly called God’s remedy.