Feastday Of Saints Michael, Gabriel And Raphael: Archangels

Today is the feastday of Michael, Gabriel and Raphael the Archangels. Here is some brief explanation of what is an angel and what are their roles in the God's plan and service against the forces of darkness - Ash
WHAT IS AN ANGEL?

"The angels are spirits," says Saint Augustine, "but it is not because they are spirits that they are angels. They become angels when they are sent, for the name angel refers to their office not to their nature.
The word "angel," comes from a Greek word angelos meaning "messenger." In the Scriptures of the Old Testament, the most frequently used name to designate the angels is mal'akh, which means, messenger or legate.
When we say the Nicene Creed:
I believe in God, the Father Almighty, Creator of Heaven and Earth, of all this is, seen and unseen.
Among those unseen things that God has created is what we call "angels". That angels exist is clear from Scripture as well as Sacred Tradition. Angels are purely spiritual creatures; they do not have bodies, and are not constrained by bodies as we are. They are personal and immortal, just as we are. They have intellects and free will, just as we do. Because an angel's mind does not depend on a body, an angel cannot forget or get confused and his will is much stronger than ours.
Every angel is a distinct being, an individual subsisting in an intellectual nature; consequently every angel is a person. The classical definition of a person, by Boethius, applies to them most perfectly: A person is an individual substance of a rational nature. Every Angel is an individuated nature, endowed with intelligence and liberty, placed outside of its cause in the world of reality. All the essential elements of an individual personality are clearly manifest in those manifold accounts of Angels appearing in this world and dealing with man, as reported in the Bible, for example, the Archangel Raphael and young Tobias; Gabriel and the Virgin Mary; Gabriel and Saint Zachary.
MICHAEL
When Satan rebelled against God, many fallen angels followed him to eternal damnation. But out of the choir of the archangel, rose a mighty angel and his name is Michael. Michael from the Hebrew mikha'el, meaning: "Who is like God?" His name is a battle cry; both shield and weapon in the struggle, and an eternal trophy of victory (Rev. 12:7). On many occasions, Satan's path crossed with that of Michael the Archangel (see Jude 1:9)
RAPHAEL
Raphael, from the Hebrew rapha: to heal, and el: God, means "God heals," or the "Divine healer." The Archangel Raphael had been sent by God to cure and comfort two afflicted souls, old Tobias and Raguel's young daughter Sara, the widow of seven husbands, all of whom had died on the first night following their wedding to her. Raphael, the Divine Healer, seems to have been at work at Jerusalem, in the days of Christ our Lord, in the pool called Bethsaida by the Sheepgate. In the five porticoes surrounding that pool there was a multitude of sick people, waiting for the action of the Angel upon the water of the pool, an action which cured immediately any person who first descended into the pool (Jn. 5:4)
GABRIEL
The name Gabriel seems to be composed of the Hebrew words, gebher: man, and el: God. It means, therefore, Man of God, or, Strength of God. Gabriel who is "the strength of God" according to Christian tradition was the Angel mentioned by Saint Luke, in his narrative of Christ's agony in the garden: "And there appeared to him an angel from heaven, strengthening him."(Lk. 22:43). It was fitting that the Angel who had witnessed the Savior's agony, and who had announced His coming to both the Old and New Testament, should also be the first to announce to the world the Savior's Resurrection, His triumph over sin and death on Easter morning: (Lk. 22: 43)
Materials and references taken from Chapter 3 of the book The Angels, by Pascal P. Parente