This sermon was delivered on Christmas Day 443 by Pope Leo the Great
The Divine goodness, dearly beloved, has indeed always taken thought for mankind in various manners, and to many degrees. God has imparted many gifts of His providence to ages past; but in these last times has exceeded all the abundance of His usual kindness, when in Christ the very Mercy has descended to sinners, the very Truth to those that are astray, the very Life to those that are dead. As a result, that Word, which is co-eternal and co-equal with the Father, takes our lowly nature into the unity of His Divinity. God, born God, becomes man, born of man.
This was indeed promised from the foundation of the world, and had always been prophesied by many signs of facts and words : but how small a portion of mankind would these types and fore-shadowed mysteries have saved, had not the coming of Christ fulfilled those long and secret promises: and had not that which then benefited but a few believers in the prospect, now benefited myriads of the faithful in its accomplishment.
Now no longer then are we led to believe by signs and types, but being confirmed by the gospel story, we worship that which we believe to have been done. Added to this, for our enlightenment, are the helps of the prophetic lore, so that we have no manner of doubt about that which we know to have been predicted by such sure oracles.
This is why the Lord says to Abraham:
In your seed shall all nations be blessed [Genesis 22:18]: hence David, in the spirit of prophecy, sings, saying:
The Lord swore truth to David, and He shall not frustrate it: of the fruit of your loins will I set upon your seat [Psalm 132]; hence the Lord again says through Isaiah:
behold a virgin shall conceive in her womb, and shall bear a Son, and His Name shall be called Emmanuel, which is interpreted, God with us [Isaiah 7:14], and again,
a rod shall come forth from the root of Jesse, and a flower shall arise from his root. [Isaiah 11:1] In which rod no doubt the blessed Virgin Mary is predicted, who sprung from the stock of Jesse and David and fecundated by the Holy Ghost, brought forth a new flower of human flesh, becoming a virgin-mother.
Let the righteous then rejoice in the Lord, and let the hearts of believers turn to God’s praise, and the sons of men confess His wondrous acts; since in this work of God especially our humble estate realizes how highly its Maker values it: in that, after His great gift to mankind in making us after His image, He contributed far more largely to our restoration when the Lord Himself took on Him
the form of a slave. [Phi. 2:7]. For though all that the Creator expends upon His creature is part of one and the same Fatherly love, yet it is less wonderful than man should advance to divine things than that God should descend to humanity.
But unless the Almighty God did deign to do this, no kind of righteousness, no form of wisdom could rescue any one from the devil’s bondage and from the depths of eternal death. For the condemnation that passes with sin from one upon all [Rom 5:12, 18] would remain, and our nature, corroded by its deadly wound, would discover no remedy, because it could not alter its state in its own strength.
For the first man received the substance of flesh from the earth, and was quickened with a rational spirit by the in-breathing of his Creator , so that living after the image and likeness [Gen 1:26] of his Maker, he might preserve the form of God’s goodness and righteousness as in a bright mirror. And, if he had perseveringly maintained this high dignity of his nature by observing the Law that was given him, his uncorrupt mind would have raised the character even of his earthly body to heavenly glory.
But because in unhappy rashness he trusted the envious deceiver, and agreeing to his presumptuous counsels, preferred to forestall rather than to win the increase of honour that was in store for him, not only did that one man, but in him all that came after him also hear the verdict:
earth you are, and unto earth shall you go [Gen 3:19];
as in the earthy, therefore,
such are they also that are earthy [1 Corinthians 15:48], and no one is immortal, because no one is heavenly.
And so to undo this chain of sin and death, the Almighty Son of God, that fills all things and contains all things, altogether equal to the Father and co-eternal in one essence from Him and with Him, took on Him man’s nature, and the Creator and Lord of all things deigned to be a mortal: choosing for His mother one whom He had made, one who, without loss of her maiden honour, supplied so much of bodily substance, that without the pollution of human seed the New Man might be possessed of purity and truth.
In Christ, therefore, born of the Virgin’s womb, though his birth was miraculous, his nature is not, on that account, different from ours. For He Who is true God, is also true man: and there is no lie in either nature.
The Word became flesh [Jn 1:14] by an elevation of the flesh, not by failure of the Godhead. His divinity conducted his power and goodness in such a way that he raised what was ours by taking it up and did not lose what was his own. In this nativity of Christ, according to the prophecy of David,
truth sprang out of the earth, and righteousness looked down from heaven.[Psalm 85]
But you, dearly beloved, whom I address in no less earnest terms than those of the blessed Apostle Peter, a chosen race, a royal priesthood, a holy nation, a people for God’s own possession [1 Peter 2:9], built upon the impregnable rock, Christ, and joined to the Lord our Saviour by His true assumption of our flesh, remain firm in that Faith [Col. 1:23], which you have professed before many witnesses [1.Tim 6:12], and in which you were reborn through water [Jn 3:5] and the Holy Ghost, and received the anointing of salvation, and the seal of eternal life.
But if any one preach to you any thing beside that which you have learned, let him be anathema [Galatians 1:9]: refuse to put wicked fables before the clearest truth, and what you may happen to read or hear contrary to the rule of the catholic and Apostolic creed, judge it altogether deadly and diabolical.
Be not carried away by their deceitful keepings of sham and pretended fasts which tend not to the cleansing, but to the destroying of men’s souls. They put on indeed a cloak of piety and chastity, but under this deceit they conceal the filthiness of their acts, and from the recesses of their ungodly heart hurl shafts [Psalm 55] to wound the simple; that, as the prophet says, they may shoot in darkness at the upright in heart.
A mighty bulwark is a sound faith, a true faith, to which nothing has to be added or taken away: because unless it is one, it is no faith, as the Apostle says,one Lord, one faith, one baptism, one God and Father of all, who is above all, and through all, and in us all [Ephesians 4:5-6] . Cling to this unity, dearly beloved, with minds unshaken, and in it follow after all holiness [Hebrews 12:14], in it carry out the Lord’s commands, because without faith it is impossible to please God, and without it nothing is holy, nothing is pure, nothing alive.
For the just lives by faith [Heb.10:38] , and he who by the devil’s deception loses it, is dead though living [1Tim 5:6], because as righteousness is gained by faith, so too by a true faith is eternal life gained, as says our Lord and Saviour. And this is life eternal, that they may know You, the only true God, and Jesus Christ, whom You have sent [John 17:3]. May He make you to advance and persevere to the end, Who lives and reigns with the Father and the Holy Spirit, for ever and ever. Amen.