Universalis: Office of Readings:
"For this reason, when our Lord was born of the Virgin, the message of the angelic voices was: Glory to God in the highest, and peace to men of good will.
For how could there be peace on earth unless Truth has arisen from the earth, that is, unless Christ were born of our flesh? And he is our peace who made the two into one: that we might be men of good will, sweetly linked by the bond of unity.
Let us then rejoice in this grace, so that our glorying may bear witness to our good conscience by which we glory, not in ourselves, but in the Lord. That is why Scripture says: He is my glory, the one who lifts up my head. For what greater grace could God have made to dawn on us than to make his only Son become the son of man, so that a son of man might in his turn become son of God?
Ask if this were merited; ask for its reason, for its justification, and see whether you will find any other answer but sheer grace."
---from A sermon of St Augustine