God didn’t spare the angels when they sinned. Instead, he sent them to hell and chained them up in dark prisons. He’s holding them there until the day of judgment.
Some of the angels abandoned their positions of authority and didn’t stay where they belonged. The Lord is keeping those angels in darkness, bound with chains that last forever, until judgment day.
Then I saw another mighty angel coming down from heaven. He was wearing a cloud like a robe and there was a rainbow above his head. His face was like the sun, and his legs were like pillars of fire.
He threw him into the Abyss, locked it, and sealed him in. This was to keep Satan from deceiving the nations anymore until the 1,000 years had ended. After that, he must be set free for a short time.