The Creed informs us of this truth; that after the death and suffering of Jesus on the cross he descended into hell (or to the dead). Many evangelical Christians who are aware of the Creeds protest the phrase because the earliest manuscripts of the Creed do not contain it and they do not find it to be a doctrine borne out by Scripture. To be fair, they are correct that it is not in the earliest manuscripts and the Scriptures are a bit unclear on the matter. We need to answer several questions:
1.) Why is there confusion on this issue?
2.) Where is the hell to which Christ descended?
3.) What Scripture references might help us to understand this reality?
4.) And ultimately, why go there?
The first question may be answered by understanding that the Christian concept of Hell cannot be read into the hebrew word "Sheol" which means the grave or the Greek word "Hades", the equivalent of the Hebrew "sheol". Thus, many of the most commonly referenced passages of Scripture by those who support the doctrine, but may not be as well versed in biblical languages, are found to be lacking any substance. For instance, Psalm 16:10 as well as Peter's two quotations of it "Thou wilt not leave my soul in Hell", is simply referring to the realm of the dead. We should not think of Christ descending into a place of torment, at least not for the purpose of being tormented. Otherwise, his words on the cross "it is finished" have little meaning. This means that a slew of "proof texts" immediately have to be tossed out. This causes confusion as to the source of the doctrine.
To answer the second, third, and fourth questions, however, we do need to realize that where Christ went he did encounter those suffering for their unbelief in this world.
"For Christ also died for sins once for all, the just for the unjust, so that he might bring us to God, having been put to death in the flesh but made alive in the Spirit. In which also he went and made proclamation to the spirits now in prison, who once were disobedient, when the patience of God kept in the days of Noah, during the construction of the ark in which a few, that is eight were saved by water." (I Peter 3:18-20)
While we do not know the physical place, or whether Hell is even a physical place, we do know that Jesus went to the place called, Gehenna, the place of torment which he mentions in Matthew 25. St. Peter teaches us that he went to proclaim the gospel to the souls which had been disobedient since days of old. But why? Is there any hope for these lost souls? No, of course not. Aside from the multiple verses that could be cited, C.S. Lewis's remark that Hell is a door locked from the inside is very helpful. The dead in Gehenna have no desire for God, for they exist in a state where there sin and rejection of him has been actualized for eternity. As hard as it is to imagine, their final rejection of God and his love causes them to desire Hell over Heaven.
If it was not for evangelization, and I think we can say for sure that Christ was not gloating in some way, what is the purpose of the descent into Hell? I think the best explanation I can give is found in verse 18 of the passage cited above. "But made alive in the Spirit." That is, his Spirit was released from the bonds of his physical body. This was true for three days until his Spirit and Body were reunited, never again to be separated. What does this teach us? I believe the moral of this clause of the Creed to be that Christ has not only been through life and death, to lead us through, he has also conquered the area between death and the Great Resurrection. That means there is literally nowhere, no time, no space between time, where we can go that Jesus has not already been. Which means there is not only nothing to fear in death, but as we wait in the presence of God for the restoration of all things and the Great Resurrection, we can be assured that we will be in place that Jesus has already visited.
This is comforting to me. Christ's descent into Hell is real and it was not for punishment, but to lead us through the last of the valleys of death.