On the Incarnation of the Lord, Against Nestorius: He continues the same line of argument drawn from the Creed of Antioch

But there follows in the Creed: “Very God of Very God; Being of one substance with the Father; by whom both the worlds were framed, and all things were made.” And when you said all this, remember that you said it all of the Lord Jesus Christ. For you find stated in the Creed: that you believe in the Lord Jesus Christ, the only begotten Son of God, and the first-born of every creature: and after this and other clauses: “Very God of Very God, Being of one substance with the Father; by whom also the worlds were framed.” How then can the same Person be God and not God; God and a statue; God and an instrument? These do not harmonize, you heretic, in any one Person, nor do they fit together, so that you can, when you like, call Him God; and when you like, consider the same Person a creation. You said in the Creed, “Very God.” Now you say: “a mere man.” How can these things fit together and harmonize so that one and the same Person may be the greatest Power, and utter weakness: the Highest glory, and mere mortality? These things do not meet together in one and the same Lord. So that severing Him for worship and for degradation, on one side, you may do Him honour as you like, and on the other, you may injure Him as you like. You said in the Creed when you received the Sacrament of true Salvation: “the Lord Jesus Christ, Very God of Very God, Being of one substance with the Father, Creator of the worlds, Maker of all things.” Where are you alas! Where is your former self? Where is that faith of yours? Where that confession? How have you fallen back and become a monstrosity and a prodigy? What folly, what madness was your ruin? You turned the God of all power and might into inanimate material and a lifeless creation: Your faith has certainly grown in time, in age, and in the priesthood. You are worse as an old man than formerly as a child: worse now as a veteran than as a tyro: worse as a Bishop than you were as a novice: nor were you ever a learner after you had begun to be a teacher.