He Preached to Those Spirits That Were in Prison

1 Peter 3:19

If you ever wondered what Christ was doing for the three days, this is the major Biblical passage letting us know.

However, there is a very old book called the Gospel of Nicodemus that gives a more robust account. It's not inspired or anything, but its portrayal of Jesus's descent is pretty wonderful:

And while all the saints were rejoicing, behold Satan the prince and chief of death said unto Hell: Make thyself ready to receive Jesus who boasteth himself that he is the Son of God, whereas he is a man that feareth death, and sayeth: My soul is sorrowful even unto death. And he hath been much mine enemy, doing me great hurt, and many that I had made blind, lame, dumb, leprous, and possessed he hath healed with a word: and some whom I have brought unto thee dead, them hath he taken away from thee. . .

But when all the multitude of the saints heard it, they spake with a voice of rebuking unto Hell: Open thy gates, that the King of glory may come in. And David cried out, saying: Did I not when I was alive upon earth, foretell unto you: Let them give thanks unto the Lord, even his mercies and his wonders unto the children of men; who hath broken the gates of brass and smitten the bars of iron in sunder? he hath taken them out of the way of their iniquity. And thereafter in like manner Esaias said: Did not I when I was alive upon earth foretell unto you: The dead shall arise, and they that are in the tombs shall rise again, and they that are in the earth shall rejoice, for the dew which cometh of the Lord is their healing? And again I said: O death, where is thy sting? O Hell, where is thy victory?

When they heard that of Esaias, all the saints said unto Hell: Open thy gates: now shalt thou be overcome and weak and without strength. And there came a great voice as of thunder, saying: Remove, O princes, your gates, and be ye lift up ye doors of hell, and the King of glory shall come in. And when Hell saw that they so cried out twice, he said, as if he knew it not: Who is the King of glory? And David answered Hell and said: The words of this cry do I know, for by his spirit I prophesied the same; and now I say unto thee that which I said before: The Lord strong and mighty, the Lord mighty in battle, he is the King of glory. And: The Lord looked down from heaven that he might hear the groanings of them that are in fetters and deliver the children of them that have been slain. And now, O thou most foul and stinking Hell, open thy gates, that the King of glory may come in. And as David spake thus unto Hell, the Lord of majesty appeared in the form of a man and lightened the eternal darkness and brake the bonds that could not be loosed: and the succour of his everlasting might visited us that sat in the deep darkness of our transgressions and in the shadow of death of our sins.

And the Lord stretching forth his hand, said: Come unto me, all ye my saints which bear mine image and my likeness. Ye that by the tree and the devil and death were condemned, behold now the devil and death condemned by the tree. And forthwith all the saints were gathered in one under the hand of the Lord. And the Lord holding the right hand of Adam, said unto him: Peace be unto thee with all thy children that are my righteous ones. But Adam, casting himself at the knees of the Lord entreated him with tears and beseechings, and said with a loud voice: I will magnify thee, O Lord, for thou hast set me up and not made my foes to triumph over me: O Lord my God I cried unto thee and thou hast healed me; Lord, thou hast brought my soul out of hell, thou hast delivered me from them that go down to the pit. Sing praises unto the Lord all ye saints of his, and give thanks unto him for the remembrance of his holiness. For there is wrath in his indignation and life is in his good pleasure. In like manner all the saints of God kneeled and cast themselves at the feet of the Lord, saying with one accord: Thou art come, O redeemer of the world: that which thou didst foretell by the law and by thy prophets, that hast thou accomplished in deed. Thou hast redeemed the living by thy cross, and by the death of the cross thou hast come down unto us, that thou mightest save us out of hell and death through thy majesty. O Lord, like as thou hast set the name of thy glory in the heavens and set up thy cross for a token of redemption upon the earth, so, Lord, set thou up the sign of the victory of thy cross in hell, that death may have no more dominion.

And the Lord stretched forth his hand and made the sign of the cross over Adam and over all his saints, and he took the right hand of Adam and went up out of hell, and all the saints followed him. Then did holy David cry aloud and say: Sing unto the Lord a new song, for he hath done marvelous things. His right hand hath wrought salvation for him and his holy arm. The Lord hath made known his saving health, before the face of all nations hath he revealed his righteousness. And the whole multitude of the saints answered, saying: Such honour have all his saints. Amen, Alleluia.