The Feast of Saints Michael, Gabriel, and Raphael, the three Archangels is September 29th.
The three archangels whom the Church honors by name are Saint Michael, Saint Gabriel, and Saint Raphael.
They are also the only three angels who are mentioned by name in Sacred Scripture.
Saint Michael the Archangel is an angel, and the leader of all angels and of the army of God. This is what the title "Archangel" means, that he is above all the others in rank. Saint Michael is the "Prince of the Heavenly Host."
Saint Michael has four main responsibilities or offices, as we know from scripture and Christian tradition.
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Speaking of Saint Michael, Pope St. John Paul II said, “His name is a synthesis that expresses the essential attitude of the good spirits. ‘Mica-EL’ in fact means: ‘Who is like God?’ In this name, therefore, we find expressed the salvific choice thanks to which the angels ‘see the face of the Father’ who is in Heaven.”
-EWTN
“Saint” indicates that one is holy, whether a human or an angel. The term is used in many ways. Saint Paul speaks in his letters of the just as “saints.” The Church speaks of canonized saints, those whose heroic virtue has been demonstrated and whose presence with God has been confirmed by their miraculous intercession.
As Saint Michael is one of the holy angels, he is a saint in both the general sense of “just,” and in the specific sense of being recognized by the Church as eternally with God.
This is also true of Saint Gabriel and Saint Raphael.
Saint Michael is mentioned several times in the Bible. He is first mentioned in the Book of Daniel where he is called “one of the chief princes” (Daniel 10:13). In the Book of Jude, he is specifically called an archangel.
The Book of Revelation says:
Now war arose in heaven, Michael and his angels fighting against the dragon; and the dragon and his angels fought, but they were defeated and there was no longer any place for them in heaven. And the great dragon was thrown down, that ancient serpent, who is called the Devil and Satan, the deceiver of the whole world—he was thrown down to the earth, and his angels were thrown down with him. (Revelation 12:7-9)
In each reference, Saint Michael is acknowledged as a warrior saint who battles evil, as well as a chief angel (archangel) responsible for other angels (understood as a portion of the ninth choir angels).
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Anyone can ask for Saint Michael’s protection, but he particularly defends against evil. Pope Leo XIII (1878-1903) had a vision of the evil that would come into the world in the coming century. In response, he wrote the Saint Michael’s Prayer and instructed it to be prayed at the end of Mass. The prayer reads:
St. Michael the Archangel,
defend us in battle.
Be our defense against the wickedness and snares of the Devil.
May God rebuke him, we humbly pray,
and do thou,
O Prince of the heavenly hosts,
by the power of God,
cast into hell Satan,
and all the evil spirits,
who prowl about the world
seeking the ruin of souls. Amen.
He is the patron saint of grocers, soldiers, doctors, mariners, first responders, and police. More importantly, he is the Guardian of the Church, as he was shown to be of Israel in the Old Testament (Daniel 10).
Saint Gabriel is an angel who serves as a messenger for God to certain people. He is one of the three archangels. Gabriel is mentioned in both the Old and the New Testaments of the Bible.
In the Old Testament, Gabriel appears to the prophet Daniel to explain his visions. Gabriel is described as, "one who looked like man," as he interprets Daniel's visions. He speaks to Daniel while he is sleeping. After Gabriel's first visit, Daniel becomes tired and sick for days. Gabriel later visits Daniel again providing him with more insight and understanding in an answered prayer.
Saint John Paul II said, “[Saint Gabriel’s] name means: ‘my power is God’ or ‘power of God,’ as if to say that the culmination of creation, the Incarnation is the supreme sign of the omnipotent Father.”
Saint Gabriel is the patron saint of telecommunication workers, radio broadcasters, postal workers, and messengers.
Saint Raphael is one of the seven Archangels who stand before the throne of the Lord, and one of the only three mentioned by name in the Bible. He appears, by name, only in the Book of Tobit. Raphael's name means "God heals." This identity came about because of the biblical story that claims he "healed" the earth when it was defiled by the sins of the fallen angels in the apocryphal book of Enoch.
Disguised as a human in the Book of Tobit, Raphael refers to himself as "Azarias the son of the great Ananias" and travels alongside Tobit's son, Tobiah. Once Raphael returns from his journey with Tobiah, he declares to Tobit that he was sent by the Lord to heal his blindness and deliver Sarah, Tobiah's future wife, from the demon Asmodeus. It is then that his true healing powers are revealed and he makes himself known as "the angel Raphael, one of the seven, who stand before the Lord". Tobit 12:15
The demon Asmodeus killed every man Sarah married on the night of the wedding, before the marriage could be consummated. Raphael guided Tobiah and taught him how to safely enter the marriage with Sarah.
Raphael is credited with driving the evil spirit from Sarah and restoring Tobit's vision, allowing him to see the light of Heaven and for receiving all good things through his intercession.
Although only the archangels Gabriel and Michael are mentioned by name in the New Testament, the Gospel of John speaks of the pool at Bethesda, where many ill people rested, awaiting the moving of the water.
"An angel of the Lord descended at certain times into the pond; and the water was moved. And he that went down first into the pond after the motion of the water was made whole of whatsoever infirmity he lay under". John 5:1-4
Because of the healing powers often linked to Raphael, the angel spoken of is generally associated with Saint Raphael, the Archangel.
-Catholic.org
Saint John Paul II said, “Finally, the third archangel is called Raphael. ‘Rafa-EL’ means: ‘God heals.’ He is made known to us by the story of Tobias in the Old Testament, which is so significant for what it says about entrusting to the angels the little children of God, who are always in need of custody, care, and protection.”
He is the patron saint of travelers, blind people, nurses, pharmacists, physicians, and people who are ill.
In the book of Tobit, we are told that as Tobias and Saint Raphael were traveling together, Tobias went to wash in the Tigris River. A fish tried to attack him, but St. Raphael told him to catch the fish and remove the heart, liver, and gall. He then used them to deliver Sarah from the demon and Tobit from his blindness.
“Brother Azarias, of what use is the liver and heart and gall of the fish?” (Raphael) replied, “As for the heart and the liver, if a demon or evil spirit gives trouble to any one, you make a smoke from these before the man or woman, and that person will never be troubled again. And as for the gall, anoint with it a man who has white films in his eyes, and he will be cured”. (Tobit 6:6-8)
It was, of course, by divine power that their spiritual and material healing was accomplished. However, the archangel in his human disguise used material means as signs, just as Christ used His spit and dirt, and the Church uses matter in the sacraments, as visible signs of spiritual realities.