On the Feast of the Nativity, Seventh Sermon

He is a true and devout worshiper of today’s festival, dearly beloved, who thinks nothing false about the Lord’s incarnation and nothing unworthy about his Godhead. For it is an equally dangerous evil to deny in him the reality of our nature or his equality with the Father in glory. So when we try to understand the mystery of Christ’s birth, in which he was born of the Virgin mother, let all the clouds of earthly reasoning be driven far away, and let the smoke of worldly wisdom be cleared from the eyes of enlightened faith. For the authority we trust is divine, and the teaching we follow is divine. Whether we turn our inward ear to the testimony of the law, or the oracles of the prophets, or the trumpet of the gospel, what the blessed John, full of the Holy Spirit, thundered out with his voice is true: “In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things were made through him, and without him nothing was made.” And just as true is what the same preacher added: “The Word became flesh and dwelt in us, and we saw his glory, the glory as of the only Son of the Father.” So in both natures it is the same Son of God, taking what is ours and not losing what is his own, renewing man in his manhood but remaining unchangeable in himself. For the Godhead he shares with the Father suffered no loss of almighty power, nor did the “form of a slave” do any wrong to the “form of God,” because the supreme and eternal essence, which lowered itself for the salvation of mankind, carried us over into its own glory, but did not cease to be what it was. That is why, when the only Son of God declares himself less than the Father and yet calls himself equal to him, he shows the reality of both forms in himself: the inequality proves the human nature, and the equality the divine. [a]

The bodily birth of the Son of God, then, took nothing from his majesty and added nothing to it, because his unchangeable substance could be neither lessened nor increased. For “the Word became flesh” does not mean that the nature of God was changed into flesh, but that the Word took the flesh into the unity of his person. And in this, beyond doubt, the whole man was taken up. Within the Virgin’s womb, made fruitful by the Holy Spirit, a virgin who was never to lose her virginity, the Son of God was so inseparably united with that man that he who was born outside time of the Father’s essence was himself born in time of the Virgin’s womb. For we could not otherwise be freed from the chains of eternal death except by his becoming lowly in our nature while he remained almighty in his own. And so our Lord Jesus Christ, true man at his birth though he never ceased to be true God, made in himself the beginning of a new creation. In the “form” of his birth he gave the spiritual life of mankind a fresh start, so that, to abolish the taint of our birth according to the flesh, there might be a possibility of rebirth without our sinful seed for those of whom it is said, “who were born not of blood, nor of the will of the flesh, nor of the will of man, but of God.” What mind can grasp this mystery, what tongue can express this gift of grace? Sinfulness returns to innocence, and the old nature becomes new. Strangers receive adoption, and outsiders enter on an inheritance. The ungodly begin to be righteous, the miserly generous, those without self-control chaste, the earthly heavenly. And where does this change come from, except from the right hand of the Most High? For the Son of God came to “destroy the works of the devil,” and he has so united himself with us, and us with him, that God’s coming down to man’s state became man’s lifting up to God’s. [b]

But in this mercy of God toward us, dearly beloved, whose greatness we cannot explain, Christians must take the greatest care not to be caught again in the devil’s tricks and tangled once more in the errors they have renounced. For the old enemy does not stop “transforming himself into an angel of light,” spreading the snares of his deceptions everywhere, and doing all he can to corrupt the faith of believers. He knows whom to ply with the zest of greed and whom to attack with the lures of the belly, before whom to set the attractions of self-indulgence and into whom to pour the poison of jealousy. He knows whom to crush with grief, whom to cheat with joy, whom to take by surprise with fear, whom to bewilder with wonder. There is no one whose habits he does not sift, whose cares he does not winnow, whose affections he does not pry into. And wherever he sees a man most absorbed in his pursuits, there he looks for a chance to harm him. Moreover, he has many whom he has bound more tightly still, because they suit his purposes, so that he may use their abilities and their tongues to deceive others. Through them are promised the healing of sickness, the foretelling of the future, the appeasing of demons, and the driving away of ghosts. To these must be added those who falsely claim that the whole course of human life depends on the influence of the stars, and that what really rests either with God’s will or with ours lies with the unchangeable fates. And yet, to do still greater harm, they promise that the fates can be changed if prayers are made to the constellations that stand against a person. So their ungodly inventions destroy themselves: if their predictions are not reliable, the fates are not to be feared; if they are, the stars are not to be revered. [c]

From this kind of teaching comes also the ungodly practice of certain foolish people who worship the sun from high places as it rises at the start of the day. Even some Christians think this so proper that, before they go into the basilica of the blessed apostle Peter, which is dedicated to the one living and true God, they climb the steps that lead up to the raised platform, turn around, and bow toward the rising sun, bending their necks to do homage to its brilliant disk. We are full of grief and distress that this happens. It comes partly from ignorance and partly from a pagan spirit. For although some of them perhaps worship the Creator of that beautiful light rather than the light itself, which is his creature, we must still keep away from even the appearance of this observance. For if someone who has given up the worship of gods finds it in our own worship, will he not go back to this piece of his old superstition, as if it were allowed, when he sees that Christians and unbelievers share it? [d]

So the faithful must give up this objectionable practice, and the honor due to God alone must not be mixed with the rites of those who serve their fellow creatures. For divine Scripture says, “You shall worship the Lord your God, and him only shall you serve.” And the blessed Job, “a man without complaint,” as the Lord says, “and one who shuns every evil,” said: “Have I looked at the sun when it shone, or at the moon walking in brightness, and has my heart rejoiced in secret, and have I kissed my hand? What is my great wrongdoing and denial against the most high God?” But what are the sun and the moon except parts of the visible creation and material light, one of greater brightness and the other of lesser light? For just as it is now daytime and now nighttime, so the Creator has set up different kinds of lights, although even before they were made there had been days without the sun and nights without the moon. But these were made to serve man, so that he, an animal endowed with reason, might be sure of the division of the months, the return of the year, and the variety of the seasons. For through the unequal length of the various periods, and the clear signs given by the changes in its rising, the sun closes the year and the moon renews the months. For on the fourth day, as we read, God said: “Let there be lights in the firmament of heaven, and let them shine on the earth, and let them divide between day and night, and let them be for signs and for seasons, and for days and years; and let them be in the firmament of heaven so that they may shine on the earth.” [e]

Wake up, O man, and recognize the dignity of your nature. Remember that you were made in the image of God, an image which, though it was corrupted in Adam, was made new again in Christ. Use visible creatures as they should be used, as you use earth, sea, sky, air, springs, and rivers, and whatever is beautiful and wonderful in them, credit to the praise and glory of their Maker. Do not make yourself subject to that light in which birds and snakes, wild beasts and cattle, flies and worms take delight. Keep the material light for your bodily senses, and with all the powers of your mind embrace that “true light which gives light to everyone who comes into this world,” of which the prophet says, “Come to him and be enlightened, and your faces will not blush.” For if we “are a temple of God, and the Spirit of God dwells in” us, what each of the faithful has in his own heart is more than what he marvels at in the sky. And so, dearly beloved, we do not tell or advise you to despise God’s works, or to think there is anything opposed to your faith in what the good God has made good, but to use every kind of creature and the whole furnishing of this world reasonably and in moderation. For, as the apostle says, “the things that are seen are temporary, but the things that are not seen are eternal.” So, because we are born for the present and reborn for the future, let us not give ourselves over to temporal goods but to eternal ones. And so that we may see our hope closer at hand, let us think on what divine grace has bestowed on our nature, on the very occasion when we celebrate the mystery of the Lord’s birthday. Let us hear the apostle saying: “For you are dead, and your life is hidden with Christ in God. But when Christ, who is your life, appears, then you also will appear with him in glory,” who lives and reigns with the Father and the Holy Spirit forever and ever. Amen. [f]