The notion that Jesus, after his death, descended into the realm of the dead in order to achieve some aim has a somewhat long and complicated history, of which I will only touch on some points. By the time 1 Peter is written (late first century), the author can refer to the fleshly death and spiritual resurrection of Jesus and to the fact that “he went and made a proclamation to the spirits in prison, who in former times did not obey, when God waited patiently in the days of Noah” (1Peter 3:18-20). The Gospel of Peter (perhaps 2nd century but maybe later) makes brief reference to a descent at the point of Jesus’ emergence from the tomb in having a voice from heaven ask Jesus, his two angelic escorts, and the walking cross, “Have you preached to them that sleep?” (10:41). The cross answers in the affirmative. The Apostles Creed of later centuries includes the descent into hell, without further clarification, among Jesus’ deeds.
Somewhat different than this preaching to the sinful people of Noah’s generation or to the sinful in hell is the very important story preserved in The Gospel of Nicodemus (aka Acts of Pilate) which reflects more detailed thinking and elaboration about this descent (available online here). In The Gospel of Nicodemus, three (Symeon and his two sons) of those who were raised from the grave (Sheol = Hades) testify to the Jewish council about what they witnessed.
According to this story, it is all of those who went to the grave (all of the dead, both good and bad) that were imprisoned under the rulership of Hades, god of the underworld. Jesus’ action in descending is what allows the righteous, including Adam, Seth, Abraham, David, Isaiah, John the Baptist, and others to make their way out of these chains and into paradise. In other words, without Jesus’ resurrection, the righteous would have remained in Hades (Sheol). In fact, when Jesus breaks through the gates of Hades, “all the dead who were bound were loosed from their chains” (21:3). In essence, the tree of knowledge brought death (through Adam), and the tree of the cross brought life (through Christ; 23-24).
Also fascinating in this gospel is the portrayal of the grave personified, namely Hades, and Satan as separate figures who debate what to do about this Jesus figure. Satan is nearly begging Hades to do something and take action against this Jesus, the “common enemy”. Hades is a bit concerned about about losing his sustenance of dead bodies, and remembers that “a certain dead man named Lazarus. . . [was] snatched . . . up forcibly from my entrails” (20:3). But, despite the stomache ache, in the end Hades turns out to be a little more realistic and rational about the (im)possibilities: “And if [Jesus] is of such power, are you able to withstand him? It seems to me that no one will be able to withstand such as he is” (20.2).
In an interesting convergence of my teaching preparations, John Calvin gave considerable attention to assessing what he thought was valuable or true in notions of Christ’s descent to hell. He clearly steers away from ideas that are also reflected in the Gospel of Nicodemus, but nonetheless sees Christ’s descent as an essential part of the story of salvation in “God’s Word” (it’s in 1 Peter and the Apostles’ Creed, after all).