The English is misleading, for “hell” has changed its sense since the English form of the Creed was fixed. Originally “hell” meant the place of the departed as such, corresponding to the Greek Hades and the Hebrew Sheol. That is what it means here, where the Creed echoes Peter’s statement that Psalm 16:10, “thou wilt not abandon my soul to Hades” (so RSV: av has “hell”), was a prophecy fulfilled when Jesus rose (see Acts 2:27-31). But since the seventeeth century “hell” has been used to signify only the state of final retribution for the godless, for which the New Testament name is Gehenna. What the Creed means, however, is that Jesus entered, not Gehenna, but Hades—that is, that he really died, and that it was from a genuine death, not a simulated one, that he rose.
— Affirming The Apostles' Creed, J.I. Packer