“For indeed He does not give aid to angels, but He does give aid to the seed of Abraham” (Hebrews 2:16).
Both humans (Romans 3:23) and angels (2 Peter 2:4) have sinned.
God has devised a plan of aid and redemption from sin for humanity but not for angels. Instead, the angels who sinned were cast down to Tartarus and delivered into chains of darkness, to be reserved for judgment (2 Peter 2:4). Because they left their proper domain, Jehovah has reserved them in everlasting chains under darkness for the judgment of the great day (Jude 6) and prepared Gehenna for the devil and his angels (Matthew 25:41).
While there are many things the Bible does not tell us about angels (Deuteronomy 29:29), it does imply these three significant and sober truths:
Like humans, angels are free moral agents who have the choice as whether they will obey God. Their prompt and precise obedience is the standard each disciple of Christ is to imitate (Matthew 6:10).
For some inexplicable reason(s), there are angels who have exercised their free will to rebel against God, instead of obeying Him. For them, seeing is not believing!
Their choice of disobedience instead of obedience is irreversible. Unlike humans, God does not have a plan of redemption for them. When they misused their free will, they received immediate and irrevocable condemnation. They understand precisely and thoroughly that “it is a fearful thing to fall into the hands of the living God” (Hebrews 10:31).
“Our God is a consuming fire” (Hebrews 12:29) who lovingly and sacrificially has provided a way of escape from the everlasting fire He has prepared for the devil and his angels (Matthew 25:41).
Mind how you go.