John the Monk, an 8th century writer, in his Hymn of the Nativity, sings of the great exchange in the mystery and wonder of the Incarnation - God becoming man in order to bring man to heaven:
Heaven and earth are united today, for Christ is born! Today God has come upon earth, and humankind gone up to heaven. Today, for the sake of humankind, the invisible one is seen in the flesh. Therefore let us glorify him and cry aloud: glory to God in the highest, and on earth peace bestowed by your coming, Savior: glory to you! Today in Bethlehem, I hear the angels: glory to God in the highest! Glory to him whose good pleasure it was that there be peace on earth! The Virgin is now more spacious than the heavens. Light has shone on those in darkness, exalting the lowly who sing like the angels: Glory to God in the highest! Beholding him [Adam] who was in Gods image and likeness fallen through transgression, Jesus bowed the heavens and came down, without change taking up his dwelling in a virgin womb, that he might refashion Adam fallen in corruption, and crying out: glory to your epiphany, my Savior and my God![Stichera (hymn) of the Nativity of the Lord]
God wants to fill our hearts anew with joy and gratitude for the greatest gift he could possibly give us his beloved son Jesus. What can we give thanks for in this great feast of the Incarnation? We can praise and thank God our Father for the fact that the Son of God freely and joyfully assumed a human nature in order to accomplish our salvation in it. Jesus came to release the captives from slavery to sin and to open the gates of paradise once again. This day the Holy Spirit invites us to make haste as the shepherds of Bethlem did to adore Jesus our King and Messiah. The Lord Jesus Christ is our eternal good shepherd who guides and cares for us unceasingly and who gives us abundant everlasting life and union with the triune God Father, Son, and Holy Spirit. This day the whole community of heaven joins with all believers of good will on earth in a jubilant song of praise for the good news proclaimed by the angels on Christmas eve: Behold, I bring you good news of a great joy which will come to all the people, for to you is born this day in the city of David a Savior, who is Christ the Lord (Luke 2:10-11).
The joy of Christmas is not for a day or a season. It is an eternal joy, a joy that no one can take from us because it is the joy of Jesus Christ himself made present in our hearts through the Holy Spirit who dwells within us (see Romans 5:2-5). The Lord gives us a supernatural joy which no pain nor sorrow can diminish, and which neither life nor death can take away.











