https://www.ampleforthabbey.org.uk/sites/default/files/cloud-of-witnesses-8-augustine-sermons.pdf

Excerpt:
St Augustine,  Sermon for Christmas Day


. Listen, children of light, adopted into the kingdom of God; most beloved brethren, listen;
listen and rejoice, you just ones, in the Lord, so that praise may rightly befit you. Listen to what
you have come to know, recall what you have heard, love what you believe, proclaim what you
love.

   Just as we celebrate this day as an anniversary, so look forward to the speech fitting for this
day. Christ has been born, God from his Father, man from his Mother. From his Father as the
source of life; from his Mother as the end of death. From his Father as one who governs every
day; from his Mother as one who consecrates the present day. From his Father timelessly; from
his Mother seedlessly. From his Father without time; from his Mother without seed. From his
Father as the source of life; from his Mother as the end of death. From his Father as the One
who orders every day; from his Mother as the One who sanctifies this day.


   He sent before Him the man John, who was to be born when the days began to shorten; and
He himself was born when the days began to lengthen, so that in this might be prefigured what
John himself said: ‘He must increase, but I must decrease.’ For human life must diminish in
itself, and prosper in Christ; that those who live, may no longer live for themselves, but for Him
who died for all and rose again. And let each of us say what the Apostle says: ‘I live now, not I,
but Christ lives in me.’ He must increase, but I must decrease.


   All his angels praise him fittingly, whose eternal food He is, giving them life through the
incorruptible sustenance He provides, for the Word of God is the source of their life, in whose
eternity they live forever, in whose goodness they live happily forever. They praise fittingly Him
who is God with God, and give glory to God in the highest.(...)


   For indeed, to these angels belongs the song we hear today, which they pour out joyfully to the
Saviour who has been born for us: ‘Glory to God in the highest, and on earth peace to people
of good will.’ So they praise Him fittingly; let us also praise Him obediently. They are his
messengers, and we are his flock. He has filled their table in heaven, and he has filled our manger
on earth. The fullness of their table comes from the fact that, in the beginning, the Word was,
and the Word was with God, and the Word was God. The fullness of our manger comes from
the fact that the Word became flesh and dwelt among us. In order that man might eat the bread
of Angels, the Creator of the Angels became man. They praise Him simply by living; we praise
Him by believing in Him; they by enjoying Him; we by seeking Him; they by possessing Him, we
by seeking Him...they by going into his presence, we by knocking at the door.


... Which of us knows all the treasures of wisdom and knowledge concealed in Christ, and
concealed in the poverty of his flesh? For He became poor for us, though He was rich, that we
might be made rich through his poverty. For when he took to Himself our mortality and
consumed death, He revealed himself in poverty; yet He promised that those riches would be
spread abroad to us; it was not that He lost them, that they were taken away from Him.


   How great is the multitude of his sweetness, which He hides from those who fear Him, but brings to perfection in those who hope in Him! For we know in part, until that which is perfect comes. In order that we might be made worthy to receive it, being equal to the Father in the form of God, He becomes like us in the likeness of a servant, reforming us to the likeness of God. And when the only Son of God becomes the Son of Man, he makes many sons of men into sons of God; and those servants of his He has nourished on the one who was in the visible form of a servant, He brings to perfection as freemen, so that they can see the form of God. For we are sons of God, and what we shall be has not yet been manifested. But we know that when He appears, we shall be like Him, for we shall see Him as He is. 

   But what are these treasures of wisdom and knowledge, these divine riches, but something that is enough for us? And what is that multitude of sweetness, except that it satisfies us? Show us, therefore, the Father, and it is enough for us.

   And in a certain psalm, one of us, or in us, or for us, says to Him: ‘I shall be satisfied when your
glory is manifested.’ But He and the Father are one; and he who sees Him, sees the Father.
Therefore, the Lord of hosts, He is the King of glory. In converting us, He will show us his face;
and we will be saved, and we will be satisfied, and it will be enough for us.

... Therefore let our heart say to Him: ‘I have sought your face; your face, Lord, I will seek; do
not turn your face away from me.’ And let Him Himself answer to our heart: ‘Anyone who loves
me keeps my commandments; and anyone who loves Me will be loved by my Father; and I will
love him and manifest myself to him.’ They certainly saw him with their eyes, and they heard
the sound of his voice with their ears, and with their human hearts, they thought of Him as a
man; but what He promised to show to those who love Him was something that eye has not seen,
that ear has not heard, and which has not arisen in the human heart. 

   Until this happens, until He shows us what is sufficient for us, until we drink and are satisfied with Him, the fountain of life, we are pilgrims in exile from Him; as we hunger and thirst for justice, and with ineffable ardour desire the beauty of the form of God, let us celebrate with devout homage the Nativity of the One who was in the form of a servant. We cannot yet contemplate what was begotten before the morning star by the Father, but let us frequent what was born of a virgin in the night hours. We cannot yet grasp that his name endures before the sun, but let us acknowledge his tent placed in the sun. We cannot yet gaze upon the Only Begotten One abiding in his Father, but let us remember the bridegroom coming forth from his bridal chamber. We are not yet worthy of the banquet of our Father, but let us acknowledge the manger of our Lord Jesus Christ.

The End.