by St. Gregory the Theologian, excerpted from a homily (Festal Oration 38) given by St. Gregory while Archbishop of Constantinople, on the Feast of the Nativity in the year 380.
Christ is born, give glory; Christ is from the heavens, go to meet Him; Christ is on earth, be lifted up. "Sing to the Lord, all the earth," and, to say both together, "Let the heavens be glad and let the earth rejoice," for the Heavenly One is now earthly. Christ is in the flesh, exult with trembling and joy; trembling because of sin, joy because of hope. Christ comes from a Virgin; women, practice virginity, that you may become mothers of Christ. Who would not worship the One "from the beginning"? Who would not glorify "the Last"?
Again the darkness is dissolved, again the light is established, again Egypt is punished by darkness. Again Israel is illumined by a pillar. Let the people siting in the darkness of ignorance see a great light of knowledge. "The old things have passed; behold, all things have become new." The letter withdraws, the spirit advances; the shadows have been surpassed, the truth has entered after them. Melchizedek is completed, the motherless One becomes fatherless; He was motherless first, fatherless second. The laws of nature are dissolved. The world above must be filled. Christ commands, let us not resist. "All nations, clap your hands," "for to us a Child is born, and to us a Son is given, the power is on His shoulder," for He is lifted up along with the cross, and He is called by the name "Angel of great counsel," that of the Father. Let John proclaim, "Prepare the way of the Lord." I myself will proclaim the power of this day. The fleshless One takes flesh, the Word is made coarse, the invisible One seen, the impalpable One is touched, the timeless One makes a beginning, the Son of God becomes a Son of Man, "Jesus Christ, the same yesterday and today and for the ages." Let Jews be scandalized, let Greeks mock, let heretics talk till their tongues ache. They will believe when they see Him ascend into heaven, and if not then, at least when they see Him coming from heaven and sitting as Judge.
by St. Gregory Palamas, Philokalia, Topics of Natural and Theological Science and on the Moral and Ascetic Life: One Hundred and Fifty Texts, 56 and 57
What, then, is the divine commandment now laid upon us? It is repentance, the essence of which is never again to touch forbidden things. We were expelled from the land of divine delight, we were justly shut out from God's paradise, and we have fallen into this pit where we are condemned to dwell together with dumb creatures without hope of returning - in so far as it depends on us - to the paradise we have lost. But He who initially passed a just sentence of punishment or, rather, justly permitted punishment to come upon us, has now in His great goodness, compassion and mercy descended for our sake to us. And He became a human being like us in all things except sin so that by His likeness to us He might teach us anew and rescue us; and He gave us the saving counsel and commandment of repentance, saying: "Repent, for the kingdom of heaven has drawn near" (Matt. 3:2). Prior to the incarnation of the Logos of God the kingdom of heaven was as far from us as the sky is from the earth; but when the King of heaven came to dwell amongst us and chose to unite Himself with us, the kingdom of heaven drew near to us all.
by St. Nicholas Cabasilas
from The Life in Christ, translated by Carmino J. deCatanzaro, St. Vladimir's Seminary Press, 1974, pp. 57-58.
It is not possible for those who have not died to sin to live for God. So it is of God alone to be able to slay sin. For men it was necessary, for had we been defeated against our will we should have been worthy of retrieving our defeat; but for those who had become slaves of sin it was in no way possible. How should we have been able to prevail over that to which we had become slaves? Even had we been more powerful, yet "the slave is not greater than the master" (Mt. 10:24).
It was man, then, who by rights should have attained this end and for whom it was fit to win the victory; but he had become enslaved by those whom he should have conquered in battle. God, however, who was indebted to no one, had the power to do these things. Therefore, as long as neither God nor man undertook the battle, sin lived on. It was impossible for the sun of the true life to rise on us, since it was man who should wrest the victory for himself but only God who was able to do so. It was necessary, therefore, for manhood to be joined to Deity, and for one and the same to possess the nature of both him to whom the warfare pertained and of Him who was able to prevail in it.