The Cross according to Saint Athansios

So much for the objections of those outside the Church. But if any honest Christian wants to know why He suffered death on the cross and not in some other way, we answer thus: in no other way was it expedient for us, indeed the Lord offered for our sakes the one death that was supremely good. He had come to bear the curse that lay on us; and how could He "become a curse"[3] otherwise than by accepting the accursed death? And that death is the cross, for it is written "Cursed is every one that hangeth on tree."[4] Again, the death of the Lord is the ransom of all, and by it "the middle wall of partition"[5] is broken down and the call of the Gentiles comes about. How could He have called us if He had not been crucified, for it is only on the cross that a man dies with arms outstretched? Here, again, we see the fitness of His death and of those outstretched arms: it was that He might draw His ancient people with the one and the Gentiles with the other, and join both together in Himself. Even so, He foretold the manner of His redeeming death, "I, if I be lifted up, will draw all men unto Myself."[6] Again, the air is the sphere of the devil, the enemy of our race who, having fallen from heaven, endeavors with the other evil spirits who shared in his disobedience both to keep souls from the truth and to hinder the progress of those who are trying to follow it. The apostle refers to this when he says, "According to the prince of the power of the air, of the spirit that now worketh in the sons of disobedience."[7] But the Lord came to overthrow the devil and to purify the air and to make "a way" for us up to heaven, as the apostle says, "through the veil, that is to say, His flesh."[8] This had to be done through death, and by what other kind of death could it be done, save by a death in the air, that is, on the cross? Here, again, you see how right and natural it was that the Lord should suffer thus; for being thus "lifted up," He cleansed the air from all the evil influences of the enemy. "I beheld Satan as lightning falling,"[9] He says; and thus He re-opened the road to heaven, saying again, "Lift up your gates, O ye princes, and be ye lift up, ye everlasting doors."[10] For it was not the Word Himself Who needed an opening of the gates, He being Lord of all, nor was any of His works closed to their Maker. No, it was we who needed it, we whom He Himself upbore in His own body—that body which He first offered to death on behalf of all, and then made through it a path to heaven.

(Complete Text of St. Athanasios' On the Incarnaion: http://www.spurgeon.org/~phil/history/ath-inc.htm)