That the Redeemer is solidary with the dead, or better, with this death which makes of the dead, for the first time, dead human beings in all reality—this is the final consequence of the redemptive mission he has received from the Father. His being with the dead is an existence at the utmost pitch of obedience, and because the One thus obedient is the dead Christ, it constitutes the “obedience of a corpse” (the phrase is Francis of Assisi’s) of a theologically unique kind. By it Christ takes the existential measure of everything that is sheerly contrary to God, of the entire object of the divine eschatological judgment, which here is grasped in that event in which it is “cast down.” But at the same time, this happening gives the measure of the Father’s mission in all its amplitude: the “exploration” of Hell is an event of the (economic) Trinity. …
If the Father must be considered as the Creator of human freedom—with all its foreseeable consequences—then judgment belongs primordially to him, and thereby Hell also; and when he sends the Son into the world to save it instead of judging it, and, to equip him for this function, gives “all judgment to the Son” (John 5:22), then he must also introduce the Son made man into “Hell” (as the supreme entailment of human liberty). But the Son cannot really be introduced into Hell save as a dead man, on Holy Saturday. This introducing is needful since the dead must “hear the voice of the Son of God,” and hearing that voice, “live” (John 5:15). The Son must “take in with his own eyes what in the realm of creation is imperfect, unformed, chaotic” so as to make it pass over into his own domain as the Redeemer. This is what Irenaeus tells us:
Propter quod et descendit ad inferiora terrae, id quod erat inoperatum conditionise visurus oculis.
This vision of chaos by the God-man has become for us the condition of our vision of the Divinity. His exploration of the ultimate depths has transformed what was a prison into a way. And so Gregory the Great can say:
Christ went down into the deepest abysses of the sea, when he went into the Lowest Hell, to fetch forth the souls of the elect. Before the redemption, the depth of the sea was a prison, not a way … But God made of this abyss a road … It is also called “the deepest abyss” on the grounds that, just as the depths of the sea cannot be fathomed by any human gaze, so too the secret of Hell is impenetrable to all human knowledge.
Yet the Lord can cross (deambulare) this deepest Hell, since he is not bound by any of the bonds of sin, but is, rather, “free among the dead.” Gregory now turns, from the depths of Holy Saturday, to consider the spiritual descent of the Redeemer into the lostness of the sinful heart: the very same descensus is repeated each time that the Lord goes down into the depths of the desperata corda. In Gregory’s footsteps, Isidore of Seville too speaks of the via in profundo maris, which opens to the elect the way of heaven. Inasmuch as the Son travels across the chaos in virtue of the mission received from the Father, he is, objectively speaking, whilst in the midst of the darkness of which is contrary to God, in “paradise,” and the image of triumph may well express this.
Today he is, as king, come to the prison; today he has broken down the doors of bronze and has snapped the bolts of iron. He who, a dead man like any other, was swallowed up, has laid Hell waste in God. [Proclus of Constantinople]
In any case, it is, as Thomas Aquinas underlines, a “taking possession.” Henceforth Hell belongs to Christ, and Christ in rising with the knowledge of Hell can communicate that knowledge to us also.