From St. Augustine

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 so that by his poverty we might become rich. When he assumed our mortality and overcame death he manifested himself in poverty: his poverty was not a sign of riches lost but a promise of riches to come later. How great is the abundance of the delights that he conceals from those who fear him but prepares for those that hope in him! Until what is being prepared arrives, we can understand only in part. To make us worthy of this perfect gift, he, equal to the Father in the form of God, became like us in the form of a servant, and he re-forms us to be like God. The only Son of God, having become the son of Man, makes many sons of men the sons of God. Taking on the form of a servant, he takes those who were born and brought up as servants and gives them the freedom of seeing the face of God. For we are the children of God, and what we shall become has not yet appeared. We know that, when he appears, we shall be like him, for we shall see him as he is. What, then, are those treasures of wisdom and knowledge? What are those divine riches unless they are what is sufficient for us? What is that multitude of delights unless it is what fills us? Show us the Father and it is sufficient enough for us. In one of the psalms one of us — either with us or on our behalf — said to him, I shall be filled when your glory appears. But he and the Father are one, and whoever sees him sees the Father also, so the Lord of hosts, he is the King of Glory. He will bring us back, he will show us his face and we shall be saved; we shall be filled, and he will be sufficient for us. Until this comes to pass, until he gives us the sight of what will completely satisfy us, until we drink our fill of him, the fountain of life — while we wander about, apart from him but strong in faith, while we hunger and thirst for justice, longing with a desire too deep for words for the beautiful vision of God, let us fervently and devotedly celebrate the anniversary of his birth in the form of a servant. We cannot yet contemplate the fact that he was begotten by the Father before the dawn, so let us hold on to the fact that he was born of the Virgin in the night. We do not yet understand how his name endures before the sun, so let us acknowledge his tabernacle placed in the sun. Since we do not, as yet, gaze upon the Only Son inseparably united with His Father, let us remember the Bridegroom coming out of his bride-chamber. Since we are not yet ready for the banquet of our Father, let us acknowledge the manger of our Lord Jesus Christ.