You must read Bishop Hilarion Alfeyev’s Christ the Conqueror of Hell.
The descent of Christ into Hades is one of the most mysterious, enigmatic and inexplicable events in New Testament history. In today’s Christian world, this event is understood differently. Liberal Western theology rejects altogether any possibility for speaking of the descent of Christ into Hades literally, arguing that the scriptural texts on this theme should be understood metaphorically. The traditional Catholic doctrine insists that after His death on the cross Christ descended to hell only to deliver the Old Testament righteous from it. A similar understanding is quite widespread among Orthodox Christians.
On the other hand, the New Testament speaks of the preaching of Christ in hell as addressed to the unrepentant sinners: ‘For Christ also died for sins once for all, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit; in which he went and preached to the spirit in prison, who formerly did not obey, when God’s patience waited’. However, many Church Fathers and liturgical texts of the Orthodox Church repeatedly underline that having descended to hell, Christ opened the way to salvation for all people, not only the Old Testament righteous. The descent of Christ into Hades is perceived as an event of cosmic significance involving all people without exception. They also speak about the victory of Christ over death, the full devastation of hell and that after the descent of Christ into Hades there was nobody left there except for the devil and demons.
How can these two points of view be reconciled? What was the original faith of the Church? What do early Christian sources tell us about the descent into Hades? And what is the soteriological significance of the descent of Christ into Hades?