Tractates on the Gospel of John

⁵ Therefore, to speak briefly, beloved, it seems to me that the Lord Jesus Christ said, “My doctrine is not mine,” meaning the same thing as if He said, “I am not from myself.” For although we say and believe that the Son is equal to the Father, and that there is not any diversity of nature and substance in them, that there has not intervened any interval of time between Him that begets and Him that is begotten, nevertheless we say these things, while keeping and guarding this, that the one is the Father, the other the Son. But Father He is not if He have not a Son, and Son He is not if He have not a Father: but yet the Son is God from the Father; and the Father is God, but not from the Son. The Father of the Son, not God from the Son: but the other is Son of the Father, and God from the Father. For the Lord Christ is called Light from Light. The Light then which is not from Light, and the equal Light which is not from Light, are together one Light not two Lights.