At the liturgical prayers of the Feast of the Nativity, the Church proclaims, “For the Father’s express Image, the Imprint of His eternity, takes the form of a servant, and without undergoing change He comes forth from a Mother who knew not wedlock. For what He was, He has remained, true God: and what He was not, He has taken upon Himself, becoming man through love for mankind.” (Stichera of the Great Vespers of the Nativity of Our Lord)