2 Peter 2:4-6
For if God did not spare sinning angels, but cast them in chains, into deep, dark dungeons to await judgment;
Revelation 2:10
Do not be afraid of the things you are about to suffer. [For] look, the devil is about to throw some of you into prison, so that you may be tested, and you will suffer persecution for ten days. [But], you should be faithful [to God] even to the point of dying [for Him], and I will give you the crown of [never ending] life.
Revelation 3:11
I am coming soon [or, suddenly. See 2:16, 25; 3:3]. Hold on firmly to what you have [i.e., opportunity, obedience, steadfastness, etc.] so that no one takes away your crown [See 2:10].