2 Peter

is a pretty interesting book.

2 Peter 2:4

Has angels that have sinned and were sent to hell but who are not considered in the same group as the third of the angels who followed Satan in his rebellion.

"For if God did not spare angels when they sinned, 

but sent them to hell, putting them in chains of darkness to be held for judgment"

The same group of angels are mentioned in

Jude 1:6

"And the angels who did not keep their positions of authority but abandoned their proper dwelling—these he has kept in darkness, bound with everlasting chains for judgment on the great Day."

Even the angels who have sinned will be judged.

How silly is it for man to think he won't be right?

2 Peter 2: 20-21 

is pretty interesting as well.

"If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and are overcome, they are worse off at the end than they were at the beginning. It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them.

Better is it to have never known the way, than to have known it and turned away from it.