All three major religions of the Western world, Christianity, Judaism, and Islam, as well as virtually all of the world's other systems of religious belief, include celestials in their cosmologies.
Their scriptures all contain references to angelic interventions. Angels, like people, belong to families or clans. Many names have been given to them, but in the opinion of a number of angel historians, the most familiar can be arranged in three categories, or spheres, starting at the top with those closest to God, and moving down to those who are connected to the physical world.
The word 'angel' itself is used both as a generic term to refer to all heavenly beings, and as a specific term to refer to the members of the third sphere, those closest to the physical. So, too, the word 'archangel' is often used as a generic term to refer to all the high orders of heavenly beings, although they are in fact but one of the higher orders.
While it looks like there is a higher and lower echelon, it's more accurate to visualize all these orders in a great circle, with the "highest" and the "lowest" holding hands. For example, seraphim, who appear to be closest to the Creator, also serve the God in us.
In the New Testament celestial beings are grouped into seven ranks: angels, archangels, principalities, powers, virtues, dominions, and thrones.
Plus, the Old Testament adds cherubim and seraphim, which with the other seven ranks, comprise the nine choirs of angels in later Christian theology; although the number has generally been fixed at seven.
The Spiritual Hierarchy
The 9 orders of angelic beings (1 being the highest order)
The First Sphere -- angels who serve as heavenly counselors
1 - SERAPHIM
2 - CHERUBIM
3 - THRONES
The Second Sphere -- angels who work as heavenly governors
4 - DOMINIONS
5 - VIRTUES
6 - POWERS
The Third Sphere -- angels who function as heavenly messengers
7 - PRINCIPALITIES
8 - ARCHANGELS
9 - ANGELS
The Nine Orders Explained
The highest order of the highest hierarchy are the seraphim, the celestial beings said to surround the throne of God, singing the music of the spheres, and regulating the movement of the heavens as it emanates from God.
Beyond the thrones are the cherubim. They are the guardians of light, and of the stars. Remote from our plane of reality, still their light touches our lives, the divine light that they filter down from Heaven.
Lucifer (Satan/Devil) is known as the 'angel of light, whom God's light shown through' - before his 'sin against God'.
The first order in the third sphere is the thrones. They are the companion angels of the planets.
The dominions are the heavenly beings who govern the activities of all the angelic groups lower than they are. Divine bureaucrats, they also serve to integrate the spiritual and the material worlds. Although they take their orders from God, and rarely contact individuals, their work is connected to our reality.
Beyond the powers are another group of beings, the virtues. They are of particular importance to us now because they are able to beam out massive levels of divine energy.
The first order of the second sphere are those beings who have been known as powers. They are the bearers of the conscience of all of humanity, the keepers of our collective history. The angels of birth and death are in this category. They are able to draw down and hold the energy of the divine plan the same way trees draw down the energy of the Sun. In this way, the powers can send all of us a vision of a world spiritual network.
Beyond the group of archangels are the principalities. They are the guardian angels of all large groups, from cities and nations to recent human creations such as multi-national corporations. These might more accurately now be called integrating angels.
Beyond the angels are the beings we are used to calling the archangels,they tend the larger arenas of human endeavor. These beings are from a different family from the angels. There are many different kinds of archangels in this larger family. The four we are most familiar with are Gabriel, Michael, Raphael, and Uriel.
The angels that we are most familiar with are those in the last order. They are the ones who are closest to humanity, the ones most concerned with human affairs. Within the category of angels, there are many different kinds, with different functions. The ones that we know best are the guardian angels.
Because of shifts in their functions and our consciousness, it is useful to think of these celestial beings as companion angels. As we enter a time of increased light and love on the planet, they will not need to guard us, but rather will be our guides to greater and greater consciousness.