St. Thomas, following St. Denis, divides the angels into three hierarchies each of which contains three orders. Their proximity to the Supreme Being serves as the basis of this division. In the first hierarchy he places the Seraphim, Cherubim, and Thrones; in the second, the Dominations, Virtues, and Powers; in the third, the Principalities, Archangels, and Angels
They were considered the highest order of the Hierarchy of Angels. They are the Angels of Love, Light, and Fire. Seraphim are the closest to God. In the Throne Room, several of the Seraphim were described as flying directly above the Throne of God and constantly sing His praise. They are also called "the Burning Ones" because they are aflame with Love. Isaiah 6 in the Old Testament speaks of the Seraphim as "having six wings; two covering the face, two covering the feet, and two were used for flying." They are associated with the color of white.
The second highest Order of Angels. Their name stands for "Wisdom" or "one who prays." In the Throne Room they were said to stand next to the Throne of God. They are also depicted on the Ark of the Covenant as its Guardians. Cherubs are the first Angels mentioned in the Bible when two Cherubs are placed by God to guard the gates to Eden with Flaming Swords. "He drove out the man; and at the east of the Garden of Eden he placed the Cherubim, and a Flaming Sword which turned every way, to guard the way to the Tree of Life." Genesis 3:24. The Cherubim were also known as the record keepers of Heaven. They were not described as the cute little "cupidlike" angels depicted by painters, but instead as having four wings.
The third ranking Order of Angels. They were also known as "Wheels" and "the Many-eyed Ones". They were considered Angels of Justice as they were said to carry out God's decisions. These Angels were often believed to be deployed like charioteers around the Throne of God. They were described in Ezekiel 1:13-19 as having four wings and four faces. They sparkled like the color of burnished brass. They had the hands of a man under their wings. Their wings were joined one to the other and they did not turn when they traveled - they all went straight forward. They had four faces. They had the face of a man as well as three other faces on their helmets - that of a lion, an ox, and an eagle. They moved on wheels in the middle of wheels, blue-green in color. Above their heads "the likeness of the firmament," which was the color of crystal, and under this were their wings, two on each side of their bodies. The noise of their wings was "like the noise of great waters."
The fourth ranking Order of Angels. According to Jewish traditions, the success or failure of nations was decided by this Order of Guardian Angels. Dionysius claims that this realm "regulates the Angels." Dominations have been described as wearing long albs, or gowns reaching to their feet, hitched with a golden belt and adorned with a green sole. They carry golden staffs in the right hand and the Seal of God in the left. At other times, they are said to hold an orb or a spectre.
The fifth ranking Order of Angels. They have been called "The Brilliant or Shining Ones." They were called the Angels of miracles, encouragement, and blessings, and were particularly involved with people struggling with their faith. Virtues have been said to be the chief bestowers of grace and valor. The two Angels at the Ascension of Jesus were traditionally believed to be from the Order of Virtues. Virtues were usually represented in a group.
The sixth ranking Order of Angels. Powers have been credited as being the first Order of Angels created by God. In Romans 13:1 it is written that "The Soul is subject to the Powers." It is their duty to protect the world from the infiltration of demons. They protect our souls from these evil beings and act as ministers of God who avenge evil in the world. It was also believed that at death, the Powers guided our transition to Heaven.
The seventh ranking Order of Angels. The Principalities were described as the Angels who protect religions. They were also considered to be the guardians over the nations and the leaders of the world. It was from this Order that the Angel who aided David in his task of slaying Goliath was thought to have come. Principalities have been described as being dressed in soldier's uniforms with golden girdles.
The eighth ranking Order of Angels. These were considered to be the Angels in command of ministering to humans. They are also the most widely known Order of Angels, since the only Angels mentioned by name in the Bible (Michael, Gabriel, and Raphael) come from this Order. They carry God's messages to humans and are ultimately in command of God's Armies of Angels who are constantly in spiritual warfare with the forces of evil and the fallen angels. Michael was almost universally believed to be their leader. The number of Archangels usually considered to be associated with our system of worlds is seven, as in the Seven Angels who stand before God in Revelation 8:2, which is often interpreted to mean the Seven Archangels. The Seven Beloved Archangels are Michael, Jophiel, Chamuel, Gabriel, Raphael, Uriel, and Zadkiel.
The ninth ranking Order of Angels. Angels are the Order closest to humanity. The word angel derives from the Greek "angelos" meaning "messenger."