The name Michael means "one who is like God." His will is focused, immovable, and entirely driven toward accomplishing goodness; he is the protector of souls, and wields his powerful sword against the poisonous and vindictive aspirations of he who is known as a liar from the beginning.
Gabriel means "God is my strength". He was sent from God to Nazareth, "to a virgin betrothed to a man named Joseph, . . . and the virgin’s name was Mary. And coming to her, he said, ‘Hail, favored one! The Lord is with you’"
Raphael means "God is my health". He is one of seven angels "who enter and serve before the Glory of the Lord." The meaning of Raphael’s name reflects the fact that he touched Tobit’s eyes in order to heal them of blindness.
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.’" 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."
Saint 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 Divine Power of God -cast into hell,
satan and all the evil spirits,
who roam throughout the world seeking the ruin of souls.