If anyone does not believe that Holy Mary is the Mother of God, he is severed from the Godhead. If anyone should assert that He passed through the Virgin as through a channel, and was not at once divinely and humanly formed in her (divinely, because without the intervention of a man; humanly, because in accordance with the laws of gestation), he is in like manner godless.
Gregory of Nazianzus...a disposition is an unsatisfactory thing unless we give it practical effect - deeds show dispositions.
Gregory of NazianzusWhat He was, He laid aside; what He was not, He assumed. He takes upon Himself the poverty of my flesh so that I may receive the riches of His divinity.
Gregory of NazianzusWhat is the right time [to discuss theology]? Whenever we are free from the mire and noise without, and our commanding faculty is not confused by illusory, wandering images, leading us, as it were, to mix fine script with ugly scrawling, or sweet-smelling scent with slime. We need actually 'to be still' (Ps. 46:10) in order to know God, and when we receive the opportunity, 'to judge uprightly' (Ps. 75:2) in theology.
Gregory of NazianzusOur starting-point must be the fact that God cannot be named... no mind has yet contained or language embraced God's substance in its fullness. No, we use facts connected with Him to outline qualities that correspond with Him, collecting a faint and feeble mental image from various quarters. Our noblest theologian is not one who has discovered the whole - our earthly shackles do not permit us the whole - but one whose mental image is by comparison fuller, who has gathered in his mind a richer picture, outline, or whatever we call it, of the truth.
Gregory of Nazianzus