I found this wonderful quote for Christmas Day from Church Father, St. John Chrysotom.
Behold on Christmas a new and wondrous reality. The angels sing and the archangels blend their voices in harmony. The Cherubim hymn their joyful praise. The Seraphim exalt Christ’s glory. 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 we who are lowly are by divine mercy raised up. Bethlehem this day resembles heaven, hearing from the stars the singing of angelic voices. Ask not how. For where God wills, nature yields. For He willed. He had the power. He descended. He redeemed. All things move in obedience to God. This day He Who is born and He Who is becomes what He is not. He is God become man, yet not departing from His Godhead.
– St. John Chrysostom
I found the quote from an article on five striking quotes on Christmas by our Church Fathers in Aleteia by Philip Kosloski. The other four quotes are also worth reading, here.