As the last stage in the divine descent (katabasis) and self-emptying (kenosis), the descent of Christ into Hades became at the same time the starting point of the ascent of humanity towards deification (theosis). Since this descent, the path to paradise is opened for both the living and the dead, which was followed by those whom Christ delivered from hell. The destination point for all humanity and every individual is the fullness of deification in which God becomes ‘all in all’. It is for this deification that God first created man and then, when ‘the time had fully come’ (Gal. 4:4), Himself became man, suffered, died, descended to Hades and was raised from the dead.
We do not know if every one followed Christ when He rose from hell. Nor do we know if every one will follow Him to the eschatological Heavenly Kingdom when He will become ‘all in all’. But we do know that since the descent of Christ into Hades the way to resurrection has been opened for ‘all flesh’, salvation has been granted to every human being, and the gates of paradise have been opened for all those who wish to enter through them. This is the faith of the Early Church inherited from the first generation of Christians and cherished by Orthodox Tradition. This is the never-extinguished hope of all those who believe in Christ Who once and for all conquered death, destroyed hell and granted resurrection to the entire human race.
Metropolitan Hilarion (Alfeyev), “Christ the Conqueror of Hell – The Descent of Christ into Hades in Eastern and Western Theological Traditions”