My favorite lines from any hymn come from "Hark, the Herald Angels Sing": Veiled in flesh, the Godhead see / Hail the incarnate Deity.
The King's College Chapel choir sings an excellent rendition of the hymn below (as does the St. Paul's Choir), but I think the hymn is best done with more gusto and strong instrumentation. This is not simply a sweet song about a little baby; it is a triumphal anthem celebrating our encounter with the King of Kings.
St. John Chrysostom echoes - or, rather, anticipates - the lyrics written by Charles Wesley. In his Christmas sermon, he nearly sings, "All join to praise this holy feast, beholding the Godhead here on earth, and man in heaven. He Who is above, now for our redemption dwells here below; and he that was lowly is by divine mercy raised."
St. John draws our attention to the wonder that, with the Incarnation, a small corner of creation holds the creator Himself: "Bethlehem this day resembles heaven; hearing from the stars the singing of angelic voices; and in place of the sun, enfolds within itself on every side, the Sun of Justice.... The Ancient of Days has become an infant. He Who sits upon the sublime and heavenly Throne, now lies in a manger. And He Who cannot be touched, Who is simple, without complexity, and incorporeal, now lies subject to the hands of men. He Who has broken the bonds of sinners, is now bound by an infant's bands."
For us whose nature He took on, this is nothing short of astonishing. "The Only Begotten, Who is before all ages, Who cannot be touched or be perceived, Who is simple, without body, has now put on my body, that is visible and liable to corruption. For what reason? That coming amongst us He may teach us, and teaching, lead us by the hand to the things that men cannot see."
If being created in the divine image did not already convey our inestimable dignity, the birth of Jesus now implies an even greater dignity. "For it was to Him no lowering to put on what He Himself had made. Let that handiwork be forever glorified, which became the cloak of its own Creator."
In the same oratorical style seen in his Easter sermon, St. John rises to a crescendo: "Come, then, let us observe the Feast.... For this day the ancient slavery is ended, the devil confounded, the demons take to flight, the power of death is broken, paradise is unlocked, the curse is taken away, sin is removed from us, error driven out, truth has been brought back, the speech of kindliness diffused, and spreads on every side, a heavenly way of life has been planted on the earth, angels communicate with men without fear, and men now hold speech with angels. "