Christos Yannaras on Our Lord Jesus Christ
We speak, then, in principle of the incarnation of God in the person of Christ, of God’s becoming man. “We say that God has become man, not that man has become God.” When we refer to Christ, we do not define someone who is essentially a man to whom the Divinity has been united; there is no preexistent human hypostasis to which God the Word has been added. But God the Word “has framed” for himself living flesh “from the pure blood of the virgin”, being himself the hypostasis which is made incarnate by this extraordinary conception. The assumption of human nature by the Word followed the way in which nature as an existential event is given effect: It has as a beginning the womb of a woman. There is formed and grows the living flesh which reveals the hypostasis or the person. We speak of the incarnation of the Son and Word of God, of the second Person of the Holy Trinity. This does not mean that the Word acts independently of the other Persons and alone effects the assumption of humanity. The Church recognizes in the event of the incarnation of God the Word a common activity of the Persons of the Holy Trinity. Not that either the Father or the Spirit are in any way made incarnate with the Word. But while the distinction of the divine Hypostases is not removed and only the Hypostasis of the Word assumes human flesh, still the will and activity of the Trinity remains common to them even with respect to the incarnation— the uniqueness of God is preserved, the unity of ‘divine life’. This single totality of life and will and activity of the Divinity is summed up by Christ in his divine-human hypostasis: “for in him the whole fullness of deity dwells bodily” (Col 2:9).
We confess Christ to be perfect God, but also perfect man. The whole Divinity is united in his person with the whole humanity. Every property and every energy of the entire human nature has been assumed by Christ, nothing human has remained outside of this assumption. The initiative for the assumption is, however, in the one who assumes, who acts singly in respect of his hypostasis and triadicly in respect of will and grace. But what is assumed is not a passive factor in the assumption. God in becoming incarnate does not compel human nature, he does not use nature as a neutral material for realizing his will. Human nature is offered to be assumed by God by a free personal consent— the nature is offered entirely and its self-offering is effected uniquely (since nature exists and is expressed only personally): It is the consent of the Virgin Mary, the free acceptance on her part of the will of God, which makes possible the meeting of the divine will with the human in the event of the incarnation of the Son and Word. “Behold, I am the handmaid of the Lord; let it be to me according to your word” (Luke 1:38).
*Taken from Elements of Faith.

