Why does the Apostles Creed mention Jesus descended into hell and the Nicene Creed says Jesus descends to the dead? Why is Jesus going to hell and the dead?

When we hear the word hell we immediately think of the place of eternal damnation for those who have rejected God in this life and have committed mortal sins without repentance. However, the word hell in the Old Testament referred to the “place of the dead.” This Hell was for both the good and the bad, the just and the unjust. Hell is a nether world, a place of darkness and a clear distinction is made in the Bible between where the good resided in hell (Hades) versus where the bad were (Gehenna), the two being separated by an impassable chasm. Recall the parable of Lazarus and the rich man in Luke 16:19. Remember also that Jesus spoke of the coming last judgment and the separating of the righteous from the evil in the parable of the sheep and the goats (Matthew 25:31). Given this understanding we believe that the sin of Adam and Eve had closed the Gates of Heaven and the holy souls who died in a state of grace awaited the redeemer in the land of the dead, or hell. These “good residing in hell” are the ones whom Jesus descends to after his death on the cross.
 
When our Lord offered his life for us on the cross, that redemptive act touches all people of every time past, present and future. Jesus is dead and buried. During this time, beginning on Good Friday, and leading up to Easter Sunday, Jesus descended among the dead: His soul joined the holy souls awaiting the Savior in the land of the dead. Jesus’ descent among the dead brought to completion the proclamation of the Gospel and liberated the holy souls who had long awaited the coming of the Messiah. The Gates of Heaven were now open and these holy souls entered into everlasting happiness in the beatific vision. Note carefully that Jesus did not deliver those souls damned to eternal punishment in hell (Gehenna) nor did He destroy hell as such; they remained in that state and place of damnation at the time of their particular judgment.