1 Peter 3:19

(It was in spirit that he went and preached the Word to the spirits who were in prison,

1 Peter 4:6

The gospel was preached for this cause to those who were dead also, that they might be judged according to men in flesh, but live according to God in spirit.

1 Peter 1:11-12

They were searching to know to what time, or to what manner of time the Spirit of Christ which was in them kept pointing, when he ever testified beforehand concerning the sufferings of Christ and the glories that would follow.

Revelation 19:10

And I fell down at his feet to worship him, and he said to me. "See that you do it not. I am a fellow slave of yours and of your brothers who hold the testimony of Jesus; for the testimony of Jesus is the vital breath of prophecy."

Revelation 20:7

And when the thousand years have been completed, Satan will be loosed out of his prison,

Treasury of Scripture Knowledge

Summary

By which also he went and preached unto the spirits in prison;

Bible References

By which

1 Peter 1:11
They were searching to know to what time, or to what manner of time the Spirit of Christ which was in them kept pointing, when he ever testified beforehand concerning the sufferings of Christ and the glories that would follow.
1 Peter 4:6
The gospel was preached for this cause to those who were dead also, that they might be judged according to men in flesh, but live according to God in spirit.
Revelation 19:10
And I fell down at his feet to worship him, and he said to me. "See that you do it not. I am a fellow slave of yours and of your brothers who hold the testimony of Jesus; for the testimony of Jesus is the vital breath of prophecy."

In

Revelation 20:7
And when the thousand years have been completed, Satan will be loosed out of his prison,