New Icon of Mother of God with Child
The Incarnation was not only the work of the Father, of His Virtue, and of His Spirit, but also the work of the will and faith of the Virgin. Without the consent of the Most-Pure One, without the agreement of her faith, this great project would have been as impossible as without the intervention of the Three divine Persons Themselves.
God took Mary for His Mother only after having instructed her and convinced her; He was thus able to take flesh from her because she freely chose to give it to Him. In the same way that God wanted to become incarnate, He wanted His Mother to bear Him freely, of her own free will.
Nicholas Cabasilas, Homily on the Annunciation