There was rebellion in Heaven. One of the angels referred to as “Lucifer, son of the morning” rose up against God desiring to be like the most High, to exalt his own “throne above the stars of God” (Isaiah 14:12-15). It was then the rebellious angel was cast out of Heaven along with one-third of the angels who rebelled against God with him (Revelation 12:4,7-9).
Angels are created beings, just as man was created. “Thou, even Thou, art LORD alone; Thou hast made heaven, the heaven of heavens, with all their host… and the host of heaven worshippeth Thee,” (Nehemiah 9:6). “Praise ye Him, all His angels: praise ye Him, all His hosts… Let them praise the name of the LORD: for He commanded, and they were created,” (Psalm 148:2,5). The number of angels God created is innumerable as recorded in Hebrews 12:22. Jesus answered the Sadducees in Matthew 22 concerning their belief that there is no resurrection, that angels do not reproduce themselves because they “neither marry, nor are given in marriage” (v. 30), neither do they die (Luke 20:35-36).
As spirit beings superior to man but inferior to God, angels were created to glorify Christ Jesus, “For by Him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by Him, and for Him: And He is before all things, and by Him all things consist,” (Colossians 1:16-17).
As created beings who neither procreate nor die, the number of angels has remained constant since their creation. Scripture does not speak of any human being becoming an angel upon death. The rank of angels as archangels, cherubim, seraphim, living creatures, ruling angels, guardian angels notes that their function and duties were fixed at their creation. The faithful angels referred to as holy and elect angels are not able to sin, while the fallen angels referred to as demons are not able NOT to sin. Being not able to sin, faithful angels have no need of salvation and therefore “the things, which are now reported unto you by them that have preached the gospel unto you with the Holy Ghost sent down from heaven; which things the angels desire to look into,” (I Peter 1:12). There is a song holy angels cannot sing, “Amazing Grace, how sweet the sound.” God “hath raised us up together, and made us sit together in heavenly places in Christ Jesus: That in the ages to come He might shew the exceeding riches of His grace in His kindness toward us though Christ Jesus,” (Ephesians 2:7). At that time the heavenly angels will get a glimpse into what it meant for Christ to have saved a wretch like me!