Angels are spirit beings who were created to glorify God and serve as his messengers.
Holy angels are, and always have been, sinless (Matthew 18:10 and Luke 9:26). They glorify God (Hebrews 1:6) by appearing before him (Job 1:6 and 2:1), praising him (Psalm 148:2), and rejoicing with him (Job 38:7). They will also enact God’s judgment during the Tribulation (Revelation 6-16).
Demons are fallen angels; they rebelled against God by wanting to be greater than him (Isaiah 14:13-14 and Ezekiel 28:15). Lucifer planned to be God, and some angels followed him. They were cast out of the 3rd heaven and are now demons. Lucifer is now called Satan, a Hebrew word for “adversary”.
Holy angels, along with Christians, will enjoy eternal life and fellowship with God in the new heavens and new earth (Isaiah 65:17-25, 66:22, 2 Peter 3:13, and Revelation 21-22), whereas demons, along with the unsaved, will suffer eternal death and separation from God (2 Thessalonians 1:6-10) in the lake of fire (Revelation 19:20, 20:10, 14-15, and 21:8).
Thank you for reading this article. May God bless you with a desire to glorify him.