(1) Hear, O sons of light, who have been received by adoption into the kingdom of God; hear, my very dear brethren; hear and be glad in the Lord, ye just ones, so that praise may become the upright.[1] Hear what you already know; reflect upon what you have heard; love what you believe; proclaim what you love. Since we are celebrating a great anniversary on this day, you may expect a sermon in keeping with the feast. Christ as God was born of His Father, as Man of His Mother; of the immortality of His Father, of the virginity of His Mother; of His Father without a mother, of His Mother without a father; of His Father without limits of time, of His Mother without seed; of His Father as the source of life, of His Mother as the end of death; of His Father ordering all days, of His Mother consecrating this particular day.[2]

(2) God sent John to earth as His human Precursor so that he was born when the days were becoming shorter while the Lord Himself was born when the days were growing longer, that in this minute detail the subsequent words of this same John might be prefigured: 'He must increase, but I must decrease.'[3] For human life ought to grow weaker in itself and stronger in Christ, that 'they who are alive may live no longer for themselves, but for him who died for all and rose again,' and that each one of us may say in the words of the Apostle: 'It is now no longer I that live, but Christ lives in me.'[4] For 'he must increase, but I must decrease.'

All His angels worthily praise Him, for He is their everlasting food, nourishing them with an incorruptible feast. He is the Word of God, by whose life they live, by whose eternity they live forever, by whose goodness they live happily forever. They praise Him worthily, as God with God, and they render glory to God on high. May we, 'his people and the sheep of his hand,'[5] reconciled to Him by our good will, merit peace in consideration of the limited measure of our weakness. For these words to which the angels themselves gave utterance in jubilation at the birth of our Saviour are their daily tribute: 'Glory to God in the highest, and on earth peace among men of good will.'[6] Therefore, they praise Him duly: let us praise Him in obedience. They are His messengers; we, His sheep. He filled their table in heaven; He filled our manger on earth. He is the fullness of their table because 'in the beginning was the Word, and the Word was with God; and the Word was God.' He is the fullness of our manger because 'the Word was made flesh, and dwelt among us.'[7] so that man might eat the Bread of angels the Creator of the angels became man. The angels praise Him by living; we, by believing; they by enjoying, we by seeking; they by obtaining, we by striving to obtain; they by entering, we by knocking.

(3) What human being could know all the treasures of wisdom and knowledge hidden in Christ and concealed under the poverty of His humanity? For, 'being rich, he became poor for our sake that by his poverty we might become rich.'[8] When He assumed our mortality and overcame death, He manifested Himself in poverty, but He promised riches though they might be deferred; He did not lose them as if they were taken from Him. How great is the multitude of His sweetness which He hides from those who fear Him but which He reveals to those that hope in Him![9] For we understand only in part until that which is perfect comes to us. To make us worthy of this perfect gift, He, equal to the Father in the form of God, became like to us in the form of a servant, and refashions us into the likeness of God. The only Son of God, having become the Son of Man, makes many sons of men the sons of God; and on these men, reared as servants, with the visible form of servants, He bestows the freedom of beholding the form of God. For 'we are the children of God, and it has not yet appeared what we shall be. We know that, when he appears, we shall be like to him, for we shall see him just as he is.'[l0] What, then, are those treasures of wisdom and knowledge? What are those divine riches unless they be that which satisfies our longing? And what is that multitude of sweetness unless it be what fills us? 'Show us the Father and it is enough for us.'[11] Furthermore, in one of the psalms, one of our race, either in our name or for our sake, said to Him: 'I shall be satisfied when thy glory shall appear.'[l2] But He and the Father are one, and the person who sees Him sees the Father also;[l3] therefore, 'the Lord of hosts, he is the King of Glory.'[l4] Turning to us, He will show us His face and 'we shall be saved';[15] we shall be satisfied, and He will be sufficient for us.

(4) Therefore, let our heart speak thus to Him; 'I have sought thy countenance; thy face, O Lord, will I still seek. Turn not away thy face from me.'[l6] And let Him reply to the plea of our hearts: 'He who loves me keeps my commandments; and he who loves me will be loved by my Father, and I will love him and manifest myself to him.'[17] Indeed, those to whom He addressed these words did see Him with their eyes; they heard the sound of His voice with their ears; they regarded Him as a man in their human heart. But, what eye has not seen, what ear has not heard, and what has not entered into the heart of man He promised to show to those who love Him.[l8] Until this favor is granted to us, until He shows us what will completely satisfy us, until we drink to satiety of that fountain of life, while we wander about, apart from Him but strong in faith, while we hunger and thirst for justice, longing with an unspeakable desire for the beautiful vision of God, let us celebrate with fervent devotion His birthday in the form of a servant. Since we cannot, as yet, understand that He was begotten by the Father before the day- star, let us celebrate His birth of the Virgin in the nocturnal hours. Since we do not comprehend how His name existed before the light of the sun, let us recognize His tabernacle placed in the sun. Since we do not, as yet, gaze upon the Son inseparably united with His Father, let us remember Him as the 'bridegroom coming out of his bride-chamber.' Since we are not yet ready for the banquet of our Father, let us grow familiar with the manger of our Lord Jesus Christ.

[1] Cf. Ps. 32.1.
[2] The Louvain manuscript adds a lengthy passage here which, though pertinent in content, is Augustinian neither in vocabulary nor in style. Cassian, in De Incarnatione 7, assigns the passage, with apparent justification, to St. Ambrose or to one of the Ambrosian School. However, the unusual brevity of this first section and the abruptness of the transition to the second seem to indicate some sort of lacuna.
[3] John 3.30.
[4] Cf. 2 Cor. 5.15; Gal. 2.20.
[5] Cf. Ps. 94.7.
[6] Luke 2.14.
[7] John 1.1,14.
[8] Cf. 2 Cor. 8.9.
[9] Cf. Ps. 30.20.
[10] I John 3.2.
[11] John 14.8.
[12] Ps. 16.15.
[13] Cf. John 10.30; 14.9.
[14] Ps. 23.10.
[15] Cf. Ps. 79.4.
[16] Cf. Ps. 26.8-10.
[17] Cf. John 14.21.
[18] Cf. 1 Cor. 2.9.