The Catechism clearly affirms, “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” (328).  Given that we do believe in angels, we define them as pure spirits and personal beings with intelligence and free will.  They are immortal beings.  As the Bible attests, they appear to humans as apparitions with a human form.

Since the 4th century, nine choirs or types of angels are identified in the Bible and have been elaborated upon by various theologians.  The first three choirs see and adore God directly.  The seraphim, which means “the burning ones,” have the most intense “flaming” love for God and comprehend Him with the greatest clarity.  (Interestingly, Lucifer, which means “light bearer,” was one of the seraphim whose beautiful light was changed into darkness.) 

The cherubim, which means “fullness of wisdom,” contemplate God’s divine providence and plan for His creatures. 

Lastly, the thrones, symbolizing divine justice and judicial power, contemplate God’s power and justice.

The next three choirs fulfill God’s providential plan for the universe.  The dominations or dominions, whose name evokes authority, govern the lesser choirs of angels. 

The virtues, whose name originally suggested power or strength, implement the orders from the dominations and govern the heavenly bodies. 

Lastly, the powers confront and fight against any evil forces opposed to God’s providential plan.

The last three choirs are directly involved in human affairs.  The principalities care for earthly principalities, such as nations or cities. 

The archangels deliver God’s most important messages to mankind, while each angel serves as a guardian for each of us.  Although not official dogma, this schema became popular in the Middle Ages in the writings of Saint Thomas Aquinas, Dante, Hildegard of Bingen, and John Scotus Erigina.

Nevertheless, we believe that Almighty God created the angels before the rest of creation. 

At some point, some angels, led by Lucifer, did rebel against God.  These angels made a free choice, radically and irrevocably rejecting God and His rule.  Therefore, they were cast into hell.  This event is mentioned, albeit briefly, in several passages of the New Testament.   Saint Peter wrote, “Did God spare even the angels who sinned?  He did not!  He held them captive in Tartarus [hell] — consigned them to pits of darkness, to be guarded until judgment” (1 Peter 2:3). 

In the Letter of Saint Jude we read, “There were angels, too, who did not keep to their own domain, who deserted their dwelling place.  These the Lord has kept in perpetual bondage, shrouded in murky darkness against the judgment of the great day. 

Sodom, Gomorrah, and the towns thereabouts indulged in lust, just as those angels did; they practiced unnatural vice.  They are set before us to dissuade us, as they undergo a punishment of eternal fire.”  When Jesus spoke of the Last Judgment and the need to serve the least of our brethren, He said to the unrighteous, “Out of my sight, you condemned, into that everlasting fire prepared for the devil and his angels” (Matthew 25:41).  Always remember that these fallen angels – the devil and demons – had been created good, but by their own free will chose to sin and turn away from God.

A key to understanding angels is by looking at what they do.  First, angels see, praise, and worship God in His divine presence.  Jesus said, “See that you never despise one of these little ones.  I assure you, their angels in heaven constantly behold my heavenly Father’s face” (Matthew 18:10), a passage which also indicates that each of us has a guardian angel.  The Book of Revelation described how the angels surround the throne of God and sing praises (Revelation 5:11, 7:11).  Moreover, they rejoice over the saved soul of the repentant sinner (Luke 15:10).

Second, angel comes from the Greek angelos which means “messenger,” which describes their role in interacting with this world.  Saint Augustine stated that angels were “the mighty ones who do His word, hearkening to the voice of His word.”  Throughout Sacred Scripture, the angels served as messengers of God, whether delivering an actual message of God’s plan of salvation, rendering justice, or providing strength and comfort.  Here are a few examples of their role as messengers in the Old Testament.  

After the fall of Adam and Eve and their expulsion, the cherubim guarded the entrance to the Garden of Eden (Genesis 3:24).  Angels protected Lot and his family in Sodom and Gomorrah (Genesis 19).  The angel stopped Abraham as he was about to offer Isaac in sacrifice (Genesis 22).  An angel guarded the people on the way to the Promised Land (Exodus 23:20).

In the New Testament, an angel appeared to the centurion Cornelius and prompted his conversion (Acts 10:1); and an angel freed Saint Peter from prison (Acts 12:1).  In all, Hebrews 1:14 captured their role well, “Are they not all ministering spirits, sent to serve those who are to inherit salvation?”

Sacred Scripture identifies by name three angels, who are the great messengers of God –  Saints Michael, Raphael, and Gabriel.  They are called archangels because of their important roles in God’s plan.  Saint Michael, whose name means “one who is like God,” led the army of angels who cast Satan and the rebellious angels into hell.  At the end of time, he will wield the sword of justice to separate the righteous from the evil (Revelation 12:7). 

Saint Gabriel, whose name means “strength of God,” announced to Mary that she had been chosen as the Mother of the Savior (Luke 1:26-38). 

Saint Raphael, whose name means “remedy of God,” cured the blind man Tobit (Tobit 5).

The angels are also our guardians.  The Catechism states, “From infancy to death human life is surrounded by their watchful care and intercession” (336).  Saint Basil (d. 379) asserted, “Beside each believer stands an angel protector and shepherd leading him to life.”  Most of us at an early age learned the little prayer to our guardian angel, “Angel of God, my guardian dear, to whom God’s love commits me here.  Ever this day be at my side, to light, to guard, to rule, to guide.”

Moreover, as Catholics, we remember the important role of Saint Michael in defending us against Satan and the powers of evil.  Toward the end of the 19th century, Pope Leo XIII (d. 1903) had a prophetic vision of the coming century of sorrow and war.  In this vision, God gave Satan the choice of one century in which to do his worst work.  The devil chose this century.  So moved was the Holy Father from this vision that he composed the prayer to Saint Michael the Archangel:  “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 power of God, thrust into Hell Satan and all the other evil spirits who roam about the world seeking the ruin of souls.”  For many years, this prayer was recited at the end of Mass.  About a year ago, our Holy Father at one of his Wednesday audiences made the strong suggestion that the recitation of the prayer be instituted at Mass once again given the great evils we see present in our world – the sins of abortion, euthanasia, terrorism, genocide, and the like.

As members of the Church, we are conscious of the angels in our liturgical practices.  At Mass, in the Preface before the Eucharistic Prayer, we join with all of the angels and saints to sing the hymn of praise, “Holy, holy, holy….”  In Eucharistic Prayer I, the priest prays, “Almighty God, we pray that your angel may take this sacrifice to your altar in heaven.”  In the Final Commendation of the Funeral Liturgy, the priest prays, “May the angels lead you into paradise; may the martyrs come to welcome you and take you to the holy city, the new and eternal Jerusalem.”  Moreover, we celebrate in our liturgical calendar the Feasts of the Archangels (September 29) and Guardian Angels (October 2).

In our daily prayers and activities, we should be mindful of these servants of God who by His love keep our lives safe from harm and guide us on the path of salvation.

from Catholic Straight Answers