To understand something of angels, we must first understand the hierarchy of angelic existence. We know from repeated scriptural assertion that Heaven is divided into higherarchies and that there are somewhat distinctive ranks associated with the makeup of the Heavenly host. While we do know the Choirs of the Angels, we really do not understand the Ranking structure of the various choirs in relation to each other. For the purposes of Human understanding we present here a basic illustration of how the choirs are assembled and leave the mystery of their ranking system to our revelation upon entry into heaven.
There are nine choirs of Angels. Scriptural reference to Angels and Angelic Choirs can be found in Isaiah, Genesis, Exodus, Ezekiel, Ecclesiastes, Daniel, I Peter, Colossians, Ephesians, I Corinthians, Jude, Tobit (Tobias), Apocalypse (Revelations), and Psalms. The nine choirs are as illustrated on the chart above and listed here in descending order: Seraphim, Cherubim, Thrones; Dominations, Virtues, Powers; Principalities, Archangels, Angels. We know that Angels will have both innate characteristics from their choir as well as individual characteristics. For Example: Angels in the hierarchy of the Seraphim have both common characteristics of those respective to their choir and individual characteristics as each Seraph is both a member of the Choir of Seraphim and an Individual Seraph. Just like each Texan may have a similar accent, and pride in Texas, this person is still an individual. It might be reasonable to equate each choir to a species such as canine, feline, porcine etc. All dogs are Canines but there are so many types of Dogs each with individual characteristics yet all Dogs have distinctive Canine characteristics. Please do not confuse this illustration with an assertion that Angels are dogs...this is simply not the case, Angels are so far beyond our general comprehension that definition of them causes one to leap from analogy to analogy in an attempt to translate such an unfathomable concept into human understanding.
We know that Angels can interact with humans as God wills it. We also can safely say that witnessing an angel must be both a wonderful and terrible thing, since EVERY scriptural reference of an angelic appearance shows the angel opening dialogue with "Fear not". I would safely state that to behold an angel must incite a fear or awestruck reaction in the witnessing human. Floating balls of light or soft hazy beams of bright light won't cause such a reaction in humans, so it's safe to say that on average angels do not choose to manifest themselves in the "warm fuzzy" greeting card form.
We also know that each choir of angel has a specific function in the service of God, and they carry out those functions in absolute certainty. Having that said, let's go on to characterize the routines of angels based upon their hierarchy. We'll group the choirs into three stages of being based on their relationship to God in Heaven. Those that Interact more with God, those that act intermediary and those that interact more with Humans. The first host, those that interact more with God than Humans, are made up of the Seraphim, Cherubim and Thrones. The second Host, those that interact with God and Humans more on an equal (in time terms not to equate Man with God!) are made up of Dominations, Virtues and Powers. The Third host we know more about as there are numerous scriptural references, leading us to believe they interact more directly with Humans (on Orders from God) and that is made up of Principalities, Archangels and Angels.
The Seraphim. The word Seraphim comes from the Hebrew term Seraph which means "to burn". The Seraphim are described in Isaiah 6 as standing on the throne where God is sitting and singing constantly the hymn of Glory; Holy, Holy, Holy. We are also told there that each Seraph has six wings, two which cover their face in the presence of God, two that cover their feet in humility in the presence of God, and 2 which they use to fly. It is natural to assume they have a somewhat humanoid form since both face and feet are mentioned here but in fact, many of God's creatures have faces and feet without having the remotest of similarities to humanoid form. We can further though suppose that they have a humanoid form because the Prophet Isaiah had his lips "burned" with a coal taken from the altar and this was done by a Seraph that withdrew the coal from the altar fire with tongs and held it in his hand. This eludes to a certain measure of manual dexterity we often equate with humans or humanoid forms. The prophet also assigns masculinity to the seraph when describing it as he uses the words, "Him" and "He" rather than choosing "It" or "the". There is no evidence though that any type of genitalia are evident, it is natural for a male to assume he is witnessing another male. How often does a Man approach an infant in green garments and make the statement "what a pretty baby, how old is he?" only to be embarrassingly informed after the fact that the infant is really female? The primary duty of the Seraphim seems to be to Sing and Praise God unceasingly. A secondary duty seems to be one of purging with fire (as illustrated by Isaias in the Bible). The absolute burning that is demonstrated by the Seraphim is a physical manifestation of Gods Eternally Burning Love.
The Cherubim. The name comes from the Hebrew Kerubh and it's actual definition is a source of much dispute for scholars. Many believing it is a Hebrew adaptation of an Assyrian Deity. They are described physically as winged Sphinxes, basically having the body of a Bull or Lion, and face of a human all in colossal proportions. The primary function of this choir is to bear the throne of God and serve as protectors. There is a description of Cherubim given along with instructions for building the ark of the covenant and God instructs Moses to make statues of Cherubim in the tabernacle to represent them as protectors of Holy things and sacred places. Cherubim are the first Angels mentioned in the Bible, in Genesis 3:23 where they are Placed before the paradise of Pleasure (Garden of Eden) and armed with flaming weapons to protect the garden from outside assault. What was outside of the Garden of Eden at that time? Satan and his "Fallen Angels". We know then that these angels must have the ability to slay other angels, and they are a definite representation of God's Power.
The Thrones. There is given no physical description of this angel. Scholars have surmised for centuries that they simply construct the very fabric of the Throne of God, and therefore share in the Glory of being tangibly close to the Magnificent God Almighty, and being the nature of God's Throne, Bore upon the Cherubim, the Thrones therefore have NO earthly interaction what so ever. They are untainted by any base or living thing.
The Dominations. Again, not a single physical description of this choir of Angels exist anywhere in known Scripture. Paul mentions them in Colossians 1:16 and it is surmised that these angels do not interact with humans but instead strive for the complete and total lordly state of being in service to God almighty, not that of Base creatures or things.
The Virtues. Saint Peter Mentions the Virtues as does Saint Paul, and they elude to the purpose of these angels to bestow and instill the Godly Virtues into mankind. It should also be noted that Saint Paul names Virtues amongst the host of Rebellious Angels that followed Satan in revolt against God, and one can easily assume that the Evil Virtues do the same function for Satan in their rebellious and "fallen" state.
The Powers. Again no physical description of these angels is presented in scripture. Since no physical description of this 2nd order of angels is present it is a safe venture that these angels do not manifest themselves visibly, but rather on a purely spiritual basis. This is in keeping with the nature of their functions. The function of Heavenly Powers is to lead those below them to the ultimate Power of God Almighty, and we must also note that this choir of angels also is named by Saint Paul as having suffered losses to Satan in the revolt in Heaven. This would make sense since Satan would have need of their function to lead those below them to the power of his Evil.
The Principalities. There is no physical description of this choir but a few passages elude to a humanoid form. Saint Jude singles out the Principalities as being the most prominent makeup of "fallen Angels" and given their duties in Heaven, it is understandable that Satan would have recruited them to his service. Saint Jude also explains that these traitors will be bound in chains for all of eternity for forsaking their function in Heaven and betraying God. The Majority of Demons (as Saint Jude points out) are most likely to be Principalities. The function of Heavenly Principalities is to demonstrate to those below them (i.e. Humans) the Lordly reign of God and to point man to the Prince of Heaven (Jesus Christ). Does it not make sense now that the function of Evil Principalities would be to point to the "Prince of Darkness"? After all, Satan's largest campaign against God is recruiting those to his own service, originally Angels, but also Mankind. Since Satan's ultimate sin was believing he was Equal to God, in an effort to "prove this lie" he must recruit as many followers as he can get so that he can stand up and say "See, they like me better!".
The Archangels. Probably the most popular and well known choir of angels. We know 3 mentioned by name in Christian Scripture with many more being named in Hebrew texts and apocryphal texts. We know that these angels interact with Humans, as in the case of Gabriel who does the service of a Herald usually announcing the coming Messiah. The Name Gabriel comes from Hebrew meaning "Man of God" or "Strength of God". We know from the implication of the name "Archangel" that this particular choir is probably superior to the last choir "Angels" but since the Archangels have much interaction with mankind, we suppose that they re considered more base or lower as a whole. It is also because of this and scriptural descriptions of them, that we can suppose Archangels bear a striking resemblance to Humans whether it is to make interaction with mankind easier for us, or because they were a "first run" model of what God ultimately made as Us humans. We do know that even though Archangels interact with humans, they can also interact with other angels, as Satan is believed from a different choir and The Archangel Michael was able to cast him out of heaven defeating Satan in a both spiritual and likely physical manner. We also know that the Archangel Raphael was able to assume human form, pretend to eat human food, and slay Demons. So we know that archangels have the power or ability to physically and finally end a demon, a power that we as Humans are not given. For the ability to slay demons would also give us the ability to slay Angels, the servants of God.
The Angels. This choir deals most directly with earthly things and mankind. When the Psalmist states that God made Man "a little less than Angels" he likely refers to both a physical appearance and a manifestation of our abilities. We know that Angels possess an amazing and superior to Human ability to destroy earthly things, as it was Angels sent by God to destroy Sodom and Gamorrah. In fact, it is safe to say that a single angel can destroy more earthly things than a single man can. Yet, Mankind has an innate nature to destroy earthly things including other Men. Because Man has freewill, he destroys with seeming impunity, whereas Angels (Heavenly) destroy only upon order from God. It can also be said that it is most likely the choir of Angels that Guardian angels come from, although there is no proof that God ONLY uses Angels for this purpose since the Archangel Raphael was sent to protect Tobit the younger, most likely because there was a demon to be slain and it is possible that Angels do not have the ability to slay higher ranking demons alone, yet probable that they can destroy demons of equal rank. We also know that Angels can heal, and can take the form of humans (as in the case of those that visited Lot and his family) but it is more likely, that these Angels already hold the appearance of humans in likely a higher form. i.e. rather than appearing as a Man, an Angel may appear as a superior specimen of Man, a more Beautiful woman, or more physically fit Man, or any combination of both. This is eluded to in that the people of Lot's town wanted to "know" these "Strangers" so irresistibly that they had effectively formed a rabble outside of Lot's home! Since Humans are attracted to more attractive Humans, it is possible Angels would have an even higher attraction for Humans.
We know that Angels (and therefore Demons) have names. All things have names, God gave them names, even the One true God has a name it is not for us to speak it. Ancient cultures believe that when you know the name of something or someone, you have power over it. It is VERY important to understand that we do not have power over Angels. Heavenly Angels are the servants of God and God would not give us any power over an Angel. He would not give us power over that which he would send to do his will on that scale. We know we do not have the power to destroy Demons, and therefore do not have the power to destroy Angels. We know that we do however have free will, and an Angel will not violate that rule. An Angel will not order us to do anything without giving us the option to ignore God's will. A Demon will only control humans when they have been invited to do so. Unfortunately, we are also sinners and constantly in a state that leaves us open to that sort of invitation. Demons can and will tempt us, doing the will of Satan, which is to ultimately see Mankind fall from grace permanently just like He has. God gives us the power to cast out demons, but not to do away with them. that having been said, Exorcism is a dangerous business not to be taken lightly. It presents both physical and spiritual danger that one should NEVER take lightly. While we do NOT have the power to destroy demons, they most certainly have the power and the ability to destroy us. It is ONLY through the Blood of Jesus Christ and the Grace of God that we can be protected from Demonic Influence, or outright physical or spiritual injury from said Demons.
We have one thing working for us that the Fallen Angels do not have, and that's the Blood of Jesus Christ. This gift is given to us by God Almighty, to allow us redemption, Jesus did not die for the Angels. He died for man. This enrages Satan and since he knows he is damned eternally, he would have man share that fate at any cost. Satan uses his followers to bring about the destruction of man, and God allows this as it is an exercise of our free will. God already has Servants that will serve him unerringly and without free will (the Heavenly Angels that did not rebel) God chose to create us to exalt him of our own free will, not for fear of punishment, or fear of damnation, but instead for sole love of Him that created all things. We should not obey the laws of man for a fear of going to prison (or worse) but instead for the love of man. Don't murder your neighbor because you love him, not because the law will put you in prison or execute you if you kill your neighbor. Don't covet his things because you love him and want him to have happiness, not because coveting his things leads to stealing or worse.
The Spiritual Battle of Armageddon is being waged as we live. Since time doesn't exist in heaven in the way we understand it, it is safe to say that this War continues during our lifetime. Scripture does not say anywhere that while God once upon a time used Angels to do his will, in the future he won't use them anymore. Angels (and Demons) exist still in this day and age. The ability to see them diminishes with the rising vanity of mankind. As we feel less likely to need God, we refuse to see God's servants, and since already behaving like Satan would have us, mankind is less likely to see the Demonic influence that exists all around us. It is too easy to ignore prayer being illegal in public schools, as the influence of Demonic Powers(the choir Powers) and more likely the separation of church and state. Fact is, Demonic influence has been taking it's toll on the world for centuries, and will continue to do so if we do not take a stand and begin using the weapons God has given us to fight this war with!