For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counselor, The mighty God, The everlasting Father, The Prince of Peace.
All Commentaries on Isaiah 9:6 Go To Isaiah 9
Augustine of Hippo
AD 430
We read, “A child is born to us,” because we see him in the nature of a servant, which he had because the Virgin conceived and brought forth a son. However, because it was the Word of God who became flesh in order to dwell among us, and because he remains what he was (that is, really God hidden in the flesh), we use the words of the angel Gabriel and call “his name Emmanuel.” He is properly called God with us to avoid thinking of God as one person and the humanity [in Christ] as another.