St. Athanasius composed one of the most important books in Christian literature, On the Incarnation, which provides a discourse on the divinity of Christ and the redemptive purpose of the Incarnation. In explaining why the Word of God became man, St. Athanasius provides five main arguments:
(i) The incarnation is the only possible sacrifice to redeem humans from their original sin
(ii) The incarnation is the means of transformation to our holy nature before the fall
(iii) The incarnation exhibits God’s immense love for us and therefore enables us to love God
(iv) The incarnation helps us live a virtuous life by seeing God Himself as an example
(v) The incarnation is the best way for God to reveal Himself to man and for man to know God
The incarnation is the only possible sacrifice to redeem humans from their original sin
St. Athanasius argues that it was not possible for God to just forgive man, when he sinned, and not let him die because “it would, of course, have been unthinkable that God should go back upon His word and that man, having transgressed, should not die.” He also excluded the possibility for God to let man perish because “it was equally monstrous that beings which once had shared the nature of the Word should perish and turn back again into non-existence through corruption”. He defended this assumption by arguing that “such indifference to the ruin of His own work before His very eyes would argue not goodness in God but limitation… It was impossible, therefore, that God should leave man to be carried off by corruption, because it would be unfitting and unworthy of Himself.”
St. Athanasius went on to exclude a third possibility, which is simply repentance of man because it “would not guard the Divine consistency, for, if death did not hold dominion over men, God would still remain untrue.” As such, the incarnation and sacrifice of our Lord Jesus Christ as the Word of God was essential to “maintain for the Father His consistency of character with all.”
After excluding the three alternatives of forgiveness without sacrifice, perishing of man, or mere repentance of man, St. Athanasius then argues that the infinite sacrifice of the Word of God has universal redemptive effect because “in His death all might die, and the law of death thereby be abolished because, having fulfilled in His body that for which it was appointed, it was thereafter voided of its power for men.”
Since the Incarnation of the Word of God was essential, “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”
St. Athanasius concluded the argument on the ransom paid by Christ by stating that “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.”
However, later in the book, St. Athanasius recognized a possible objection to his first argument, since we still die, even Christians go through the same death punishment due to the original sin. To this objection, St. Athanasius explained the effect of the redemption of Christ that “when we die we no longer do so as men condemned to death, but as those who are even now, in process of rising, we await the general resurrection of all.”
The incarnation is the means of transformation to our holy nature before the fall
The second main argument by St. Athanasius on why the Word of God became man is that we couldn’t be restored to our incorruptible nature before the fall except through Christ taking a human body. Simply repenting doesn’t solve the problem that our nature is still corruptible:
Nor does repentance recall men from what is according to their nature; all that it does is to make them cease from sinning. Had it been a case of a trespass only, and not of a subsequent corruption, repentance would have been well enough; but when once transgression had begun men came under the power of the corruption proper to their nature and were bereft of the grace which belonged to them as creatures in the Image of God. No, repentance could not meet the case.
Therefore, the Word of God became incarnate, died for our sins, and resurrected, so that
He might turn again to incorruption, men who had turned back to corruption, and make them alive through death by the appropriation of His body and by the grace of His resurrection… 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.
The incarnation exhibits God’s immense love for us and therefore enables us to love God
After finishing the first two main arguments, St. Athanasius provided spiritual arguments for the Incarnation of the Word. One of these arguments is that the Incarnation reveals God’s immense love to us, and therefore enables us to love God. He explains that God “pitying our race, moved with compassion for our limitation, unable to endure that death should have the mastery, rather than that His creatures should perish and the work of His Father for us men come to nought.” God therefore “surrendered His body to death instead of all, and offered it to the Father. This He did out of sheer love for us.” Without the Incarnation of God and His sacrifice for us, how can we be assured that He loves us? Jesus went through torture and death to save us from eternal damnation and, therefore, He made it possible for us to love God in a much deeper way than any religion or philosophy offers. In no other religion do we find believers renouncing material luxuries, and enduring torture and death for their faith, than in Christianity. This is only possible because only Jesus has provided an example for us, and given us of eternal life in Him.
The incarnation helps us live a virtuous life
One of the spiritual arguments that St. Athanasius mentioned is that humans were knee-deep in sin and wickedness. God “saw how the surpassing wickedness of men was mounting up against them”, and therefore “corrected their neglect by His own teaching”. Before Christ, “impiety and lawlessness were everywhere, and neither God nor His Word was known.” Therefore,
Three ways thus lay open to them, by which they might obtain the knowledge of God. They could look up into the immensity of heaven, and by pondering the harmony of creation come to know its Ruler, the Word of the Father, Whose all-ruling providence makes known the Father to all. Or, if this was beyond them, they could converse with holy men, and through them learn to know God, the Artificer of all things, the Father of Christ, and to recognize the worship of idols as the negation of the truth and full of all impiety. Or else, in the third place, they could cease from lukewarmness and lead a good life merely by knowing the law…Yet men, bowed down by the pleasures of the moment and by the frauds and illusions of the evil spirits, did not lift up their heads towards the truth.
The incarnation is the best way for God to reveal Himself to man and for man to know God
Finally, St. Athanasius mentions the deep yearning in each human to know and see God. At the same time, God too wanted to reveal Himself to man out of His love for us. It was the Incarnation that would make this happen. As St. Athanasius explained
Then God the Almighty was making mankind through His own Word, He perceived that they, owing to the limitation of their nature, could not of themselves have any knowledge of their Artificer, the Incorporeal and Uncreated. He took pity on them, therefore, and did not leave them destitute of the knowledge of Himself, lest their very existence should prove purposeless.
St. Athanasius argued for God’s purpose to reveal Himself to us otherwise “why should God have made them at all, if He had not intended them to know Him?”.
For man, seeing and knowing God is the only way to live a happy life: “through Him to apprehend the Father; which knowledge of their Maker is for men the only really happy and blessed life.” Otherwise, “what was the use of their ever having had the knowledge of God? Surely it would have been better for God never to have bestowed it, than that men should subsequently be found unworthy to receive it.”
As such, St. Athanasius concludes by questioning “what else could He possibly do, being God, but renew His Image in mankind, so that through it men might once more come to know Him? And how could this be done save by the coming of the very Image Himself, our Savior Jesus Christ? Men could not have done it, for they are only made after the Image; nor could angels have done it, for they are not the images of God.”
Another important point that St. Athanasius mentions is the fact that humans mostly understand through their senses. God, knowing this, “in His great love took to Himself a body and moved as Man among men, meeting their senses, so to speak, half way. He became Himself an object for the senses, so that those who were seeking God in sensible things might apprehend the Father through the works which He, the Word of God, did in the body.”
The incarnation also provides humans with answers to many of their questions:
Did their minds tend to regard men as Gods? The uniqueness of the Savior’s works marked Him, alone of men, as Son of God. Were they drawn to evil spirits? They saw them driven out by the Lord and learned that the Word of God alone was God and that the evil spirits were not gods at all. Were they inclined to hero-worship and the cult of the dead? Then the fact that the Savior had risen from the dead showed them how false these other deities were, and that the Word of the Father is the one true Lord, the Lord even of death… For this reason He did not offer the sacrifice on behalf of all immediately [after] 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”