Tractates on the Gospel of John

⁷ This sentence overthrows the Sabellian heresy. The Sabellians have dared to affirm that the Son is the very same as He who is also the Father: that the names are two, but the reality one. If the names were two and reality one, it would not be said, “My doctrine is not mine.” Anyhow, if Your doctrine is not Yours, O Lord, whose is it, unless there be another whose it is? The Sabellians understand not what You said; for they see not the trinity, but follow the error of their own heart. Let us worshippers of the trinity and unity of Father, Son, and Holy Ghost, and one God, understand concerning Christ's doctrine, how it is not His. And He said that He spoke not from Himself for this reason, because Christ is the Son of the Father, and the Father is the Father of Christ; and the Son is from God the Father, God, but God the Father is God not from God the Son.