Of One Substance with Father and Mother

But in your deceit and blasphemy you use a grand argument for denying and attacking the Lord God, when you say that “the child born ought to be of one substance with the mother.” I do not entirely grant it, and I hold that in the matter of God’s birth it would not apply. For the birth was not so much the work of her who bore him as of her Son, and he was born as he willed, since it was his own doing that he was born. Next, if you say that the child born ought to be of one substance with the parent, I affirm that the Lord Jesus Christ was of one substance with his Father, and also with his mother. For in keeping with the difference between the persons, he showed a likeness to each parent: according to his divinity he was of one substance with the Father, and according to the flesh he was of one substance with his mother. Not that it was one person who was of one substance with the Father and another who was of one substance with his mother. Rather, the same Lord Jesus Christ, both born as man and being God, had in him the properties of each parent: as man he showed a likeness to his human mother, and as God he possessed the very nature of God the Father. [a]