A Brief Doctrine of Angels
According to scripture, angels are created, spiritual beings (Psalm 148). Created by God and chosen to carry out many of His purposes (Psalm 103:20). As we see in the fall of Lucifer and a third of the Heavenly host's, angels were created with a will of their own.
It's important to note that when the scripture talks about demons, it is referring to those fallen angels who rebelled against God. Although a natural point to overlook, demons as fallen angels help us in our understanding of certain characters in the scriptures. For example, when Jesus casts out Legion in the Gospels, He is confronting fallen angels.
Angel, whether good or evil, is a term that means messenger. New Testament writers use the term angels (Matthew 24:36) as well as Heavenly Hosts (Luke 2:13) or Spirits as we see in Hebrews 1. We can see their responsibility to be messengers throughout scripture whether it's an angel appearing to people in the Old Testament or the angel visiting Mary in the intertestamental period or the angels visiting the women at the tomb after Jesus had risen from the dead. Each time these messengers of God brought important news to humanity.
Angels possess intelligence (2 Corinthians 11:3). They exercise will (Jude 6). Paul refers to them as invisible in Colossians 1:16, and yet they appear to men and women in physical form (Mark 16:5). How angels appear varies. In some cases, they appear as light while in other circumstances as human beings. As Christians, we are commanded to be hospitable for many reasons, one of which is that we may be entertaining angels unaware (Hebrews 13:2).
The writer of Hebrews (1:4) also tells us that Christ is superior to the angels, which should go without saying, but the writer of Hebrews makes a particular case for this. As human beings, our relation to angels is quite unique as we were created a little lower than the Angels, according to Psalm 8:5. And yet someday we, the Saints, will judge angels (1 Cor. 6:3-4).
Several more interesting facts about angels include that they praise and honor God (Hebrews 1:6, Psalm 148:2, and Revelation 5). They do not receive worship themselves (Revelation 22:9). Angels are recorded as ministering to the needs the believers (Acts 5:19, 12:6-11). In the Book of Daniel, angels wage war over certain earthly regions (Daniel 10:13). And keeping in line with warring over certain areas, angels also execute God's judgment on those who oppose Him (Acts 12:23, Revelation 8, 9, 16, and 19). Scripture doesn't speak of angels in a female form. Nor does it portray them as being winged necessarily. The only exception being the Seraphim in Isaiah 6 and the Cherubim in Exodus 25:20.
There's one last classification of angels that is of interest; the elect angels in 1 Timothy 5:21. With constant debate in soteriology about election and reprobation, this class of angel seems to fit with either the notion of elect to service or simply in line with those who chose God and did not rebel.