The very Word of God, more ancient than the ages, the invisible, the incomprehensible, the incorporeal, the principle issuing from principle, the light born of light, the source of life and of immortality, the imprint of the divine model, the immutable seal, the perfect image, and the definitive word of the Father proceeds toward his own image, clothes himself with flesh to save the flesh, unites a thinking soul to himself for the sake of my soul so as to purify the like by the like, and assumes all that is human with the exception of sin.

He who is fullness empties himself. He empties himself at the moment of his glory to enable me to share his fullness.

—Gregory of Nazianzus, Discourses 45

It is, therefore, with an unmistakable tenderness that so great a wealth of divine goodness has been poured out on us, dearly beloved. Not only has the usefulness of foregoing examples served in calling us to eternity, but the Truth himself has even “appeared” in a visible body. We ought, then, to celebrate this day of the Lord’s birth with no listless and worldly joy.

—Leo the Great, Sermons 23.5