This is what Holy Scripture tells us, proclaiming the command of God, "Of every tree that is in the garden thou shalt surely eat, but of the tree of the knowledge of good and evil ye shall not eat, but in the day that ye do eat, ye shall surely die." "Ye shall surely die"—not just die only, but remain in the state of death and of corruption.
As we have already noted, it was unthinkable that God, the Father of Truth, should go back upon His word regarding death in order to ensure our continued existence. He could not falsify Himself; what, then, was God to do?
The Word perceived that corruption could not be got rid of otherwise than through death; yet He Himself, as the Word, being immortal and the Father's Son, was such as could not die. For this reason, therefore, He assumed a body capable of death, in order that it, through belonging to the Word Who is above all, might become in dying a sufficient exchange for all, and, itself remaining incorruptible through His indwelling, might thereafter put an end to corruption for all others as well, by the grace of the resurrection. It was by surrendering to death the body which He had taken, as an offering and sacrifice free from every stain, that He forthwith abolished death for His human brethren by the offering of the equivalent. For naturally, since the Word of God was above all, when He offered His own temple and bodily instrument as a substitute for the life of all, He fulfilled in death all that was required. Naturally also, through this union of the immortal Son of God with our human nature, all men were clothed with incorruption in the promise of the resurrection. For the solidarity of mankind is such that, by virtue of the Word's indwelling in a single human body, the corruption which goes with death has lost its power over all.
When, then, the minds of men had fallen finally to the level of sensible things, the Word submitted to appear in a body, in order that He, as Man, might center their senses on Himself, and convince them through His human acts that He Himself is not man only but also God, the Word and Wisdom of the true God. This is what Paul wants to tell us when he says: "That ye, being rooted and grounded in love, may be strong to apprehend with all the saints what is the length and breadth and height and depth, and to know the love of God that surpasses knowledge, so that ye may be filled unto all the fullness of God." The Self-revealing of the Word is in every dimension—above, in creation; below, in the Incarnation; in the depth, in Hades; in the breadth, throughout the world. All things have been filled with the knowledge of God.
For this reason He did not offer the sacrifice on behalf of all immediately He came, for if He had surrendered His body to death and then raised it again at once He would have ceased to be an object of our senses. Instead of that, He stayed in His body and let Himself be seen in it, doing acts and giving signs which showed Him to be not only man, but also God the Word. There were thus two things which the Savior did for us by becoming Man. He banished death from us and made us anew; and, invisible and imperceptible as in Himself He is, He became visible through His works and revealed Himself as the Word of the Father, the Ruler and King of the whole creation.
Have no fears then. Now that the common Savior of all has died on our behalf, we who believe in Christ no longer die, as men died aforetime, in fulfillment of the threat of the law. That condemnation has come to an end; and now that, by the grace of the resurrection, corruption has been banished and done away, we are loosed from our mortal bodies in God's good time for each, so that we may obtain thereby a better resurrection. Like seeds cast into the earth, we do not perish in our dissolution, but like them shall rise again, death having been brought to nought by the grace of the Savior.
In a word, then, those who disbelieve in the resurrection have no support in facts, if their gods and evil spirits do not drive away the supposedly dead Christ. Rather, it is He Who convicts them of being dead. We are agreed that a dead person can do nothing: yet the Savior works mightily every day, drawing men to religion, persuading them to virtue, teaching them about immortality, quickening their thirst for heavenly things, revealing the knowledge of the Father, inspiring strength in face of death, manifesting Himself to each, and displacing the irreligion of idols; while the gods and evil spirits of the unbelievers can do none of these things, but rather become dead at Christ's presence, all their ostentation barren and void. By the sign of the cross, on the contrary, all magic is stayed, all sorcery confounded, all the idols are abandoned and deserted, and all senseless pleasure ceases, as the eye of faith looks up from earth to heaven. Whom, then, are we to call dead? Shall we call Christ dead, Who effects all this? But the dead have not the faculty to effect anything. Or shall we call death dead, which effects nothing whatever, but lies as lifeless and ineffective as are the evil spirits and the idols? The Son of God, "living and effective," is active every day and effects the salvation of all; but death is daily proved to be stripped of all its strength, and it is the idols and the evil spirits who are dead, not He. No room for doubt remains, therefore, concerning the resurrection of His body.
In short, such and so many are the Savior's achievements that follow from His Incarnation, that to try to number them is like gazing at the open sea and trying to count the waves. One cannot see all the waves with one's eyes, for when one tries to do so those that are following on baffle one's senses. Even so, when one wants to take in all the achievements of Christ in the body, one cannot do so, even by reckoning them up, for the things that transcend one's thought are always more than those one thinks that one has grasped.
If this has whet your appetite, you can read the whole work here: