There is much obscurity in the popular mind as to the origin and nature of Satan, and as Scripture is its own interpreter, a few passages on the subject of "fallen angels" may give a ray of light to those who desire it.
Evil angels were not created as such, but fell from their first estate through sin: "God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment." (2 Peter 2:4)
The instigator of this revolt was the most exalted angel in heaven, second only to the Son of God. To him it was said: "You seal up the sum, full of wisdom, and perfect in beauty. You have been in Eden, the garden of God. ... You are the anointed cherub that covers; and I have set you so. ... You were perfect in your ways from the day that you were created, till iniquity was found in you." (Ezekiel 28:12-15)
The sin of Satan was pride: "Your heart was lifted up because of your beauty." (Ezekiel 28:17) "How are you fallen from heaven, O Lucifer, son of the morning! ... For you have said in your heart, ... I will exalt my throne above the stars of God; I will sit also upon the mount of the congregation, in the sides of the north; I will ascend above the heights of the clouds; I will be like the Most High." (Isaiah 14:12-14)
In consequence of Satan's sin, there was war in heaven: "Michael [Christ] and His angels fought against the dragon; and the dragon fought and his angels, And prevailed not; neither was their place found any more in heaven." (Revelation 12:7-8)
They were cast out into the earth: "And the great dragon was cast out, that old serpent, called the Devil and Satan, which deceives the whole world: he was cast out into the earth, and his angels were cast out with him." (Revelation 12:9)
They never repent, but are "reserved in everlasting chains under darkness unto the judgment of the great day." (Jude 6)
Satan shows his enmity toward the Son of God by accusing and persecuting those for whom Christ shed His blood. (See Revelation 12:10,17) Satan and fallen angels will finally be destroyed, together with wicked men: "Then shall He say also unto them on the left hand, Depart from me you cursed, into everlasting fire, prepared for the devil and his angels." (Matthew 25:41)
They will be cut off, root and branch: "For, behold the day comes, that shall burn as an oven: and all the proud, yea, and all that do wickedly, shall be stubble: and the day that comes shall burn them up, says the Lord of hosts, that it shall leave them neither root nor branch." (Malachi 4:1)--Present Truth, August 7, 1902--This article is referred to in article 123, "The Personality of Satan"--By Augusta W. Heald.