Christ explains why he willingly undergoes death

For I am the good shepherd who lays down his life for the sheep of his own free will (John 10:11). Just as, though I existed in the form of God, I emptied myself and took the form of a servant with no one forcing me (Philippians 2:6-7), so also I endure death willingly—not overpowered by force, but coming to the passion of my own free will. “Why then did you suffer, Master?” “For the salvation of human beings,” he says. And I will tell you the manner of it. Since the human race was made subject to the sentence of death through Adam, who was formed from virgin earth, and since I was the one who had cast out the sentence of death, it was impossible for the human being to be released from the punishment unless I myself recalled my own sentence. For this reason I took human form from a virgin womb, in the likeness of Adam, and I endure death, so that as God I may dissolve the sentence, and as a human being I may accept death on behalf of human beings. I do this so that I may set humanity free not by authority but by compassion. For if a human being had sinned and God had set things right, the achievement would not have been great. But as it is, for this reason I became a human being, and on behalf of the one who broke the law I fulfilled the law, so that the human race might glory in the kinship of the one who set things right. Therefore even now I receive the sentence of death on behalf of Adam, so that through me he may receive the grace of the resurrection. Adam stumbled and brought death in with him; I set things right and brought the resurrection in against it. And since death reigned from Adam until Moses (Romans 5:14)—and it reigned by holding the body subject as the co-worker of sin—for this reason I took up that same body which seemed to be the instrument of sin, so that by abolishing sin I might show the human being free from sin. And in another way: since human beings were living an evil life, entangled with sin, so that their life was worse than death, for this reason I chose the good death over the evil life and endure death, so that those who share in the good death may enjoy the true life. And they enjoy it through baptism. For all who are baptized are baptized into my death, so that just as I was raised from the dead, so also they may walk in newness of life (Romans 6:3-4). And let no one doubt and say, “Darkness does not produce light, nor does black produce whiteness—how then did death give birth to life?” That the matter is beyond nature is clear. But in my case do not look for the order of nature. For I am the master of nature, sometimes allowing nature to run according to nature, and sometimes driving it beyond nature. For whenever I wish to accomplish something extraordinary, then nature denies its own order and does whatever my command directs. And this is clear from the visible order of creation—I mean something like this: the sun and the moon are fire by nature, and the frozen water is a firmament, which I called heaven. If you look for the course of nature, how is the fire guarded by the water, or how is the frozen firmament not dissolved and melted by the heat of the fire? And so that I may not occupy your soul with the visible order of creation, I will lead you by the hand to the plan of salvation itself and persuade you that in paradoxical wonders one must not look for the course of nature. Consider that though I was God, I put on a human body. This is first of all beyond nature. For tell me, how could the human body, extended in three dimensions, contain the one who cannot be contained, the one without measure, the one who is everywhere, the one who circumscribes the whole world, the one who measures the heaven with a span and the earth with a handful and the sea with a cup (Isaiah 40:12)? That it did contain him is clear, since all the fullness of divinity dwelt in the flesh bodily (Colossians 2:9). But how—I know, he says. For I know what I arrange in my plan of salvation, but you cannot hear it. For the knowledge of ineffable things surpasses mortal hearing, so much so that even when I wish to explain something because of the abundance of my mercies, I explain it not as nature has it, but as you are able to learn. For this reason, putting down the pride of those who seem wise, I said: “The one who thinks he knows something does not yet know as he ought to know” (1 Corinthians 8:2). For you have heard that though I was the Word, I became flesh, but how—you do not know. How was I in the flesh—as a body in a body, or as a soul in a body? I shared in the suffering of the passible body, then, but I did not suffer. For the nature of God does not fall into passion. Just as I became flesh without ceasing to be God, so also I endured the passion without falling into passion. I was born for the plan of salvation; I died for the salvation of human beings. Rather, I died for this reason: because I was born.