Q: Gregory of Nazianzus, is there any difference between the will of the Son and of the Father?
A: "There is no difference at all between the will of the Son and of the Father. For the Son is the image of the goodness [of God], according to the beauty of the original. When someone gazes into a mirror...., his image conforms in every detail to the original that caused the image in the mirror. The mirror-image cannot move unless the movement originates in the original. And when the original moves, the mirror-image, by necessity, moves in the same way.
Just so is the Lord, 'the image of the invisible God', immediately and inseparably united to the Father whose will he obeys in every moment. The Father wills something. The Son, who is in the Father, wills the same as the Father; or more precisely: he himself becomes the will of the Father. For if he possesses in himself all that the Father possesses, then there is nothing in the Father that he would not possess. And if he has in himself all that belongs to the Father, or rather: the Father himself, and with the Father everything that belongs to the Father, then he also possesses in himself the will of the Father in its entirety."