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.
Michael the archangel, whose name in Hebrew means "Who is like God?", is revered as the leader of the angelic army who will conquer Satan and his armies of demons, and is considered the defender of the Church. Michael is more often represented in art thank any other angelic being. He is often shown wearing armor, in the act of slaying the great Dragon of the Apocalypse [Satan] in Revelation 12:7-9.
The archangel Gabriel, whose name in Hebrew means "Strength of God", announced the birth of John the Baptist to Zachariah, and soon after, announced to Mary that she was to become the mother of Our Lord. His address to her, "Hail, full of grace, the Lord is with thee" (the "angelic salutation") is familiar to all who say the Rosary.
The archangel Raphael, whose name means medic or ointment of God, is mentioned by name in the Old Testament book of Tobit (Tobias), whom the angel aided by healing him of blindness and guiding him on his travels.
Catechism of the Catholic Church
A Prayer to Saint Michael
Saint Michael, 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, thrust into hell Satan and all the other evil spirits who prowl about the world seeking the ruin of souls. Amen.
Pope Leo XIII