John 8:27

The Spirit-clad is astonishment-stricken at the senselessness of the Jews, and with great reason: for what more without understanding than such, who, when much discourse and often had been made to them concerning God the Father, conceive not of Him a whit when they hear our Saviour saying, But He That sent Me is True? What then is the plea, and why the blessed Evangelist says that the Jews knew not that Christ in these words signified God the Father to them, we must needs say.

Every soul, as being a thing, is mutable; and although a great creature, yet a creature; though superior to the body, yet made. Every soul, then, since it is changeable-that is, sometimes believes, sometimes disbelieves; at one time wishes, at another time refuses; at one time is adulterous, at another chaste; now good, and again wicked,-is changeable. But God is that which is, and so has retained as His own peculiar name, "I am who am." Such also is the Son, when He says, "If ye believe not that I am;" and thereto pertains also, "Who art thou? The Beginning." God therefore is unchangeable, the soul changeable. When the soul receives from God the elements of its goodness it becomes good by participation, just as by participation thine eye seeth. For it sees not when the light is withdrawn, while so long as it shares in the light it sees. Since then by participation the soul is made good, if it changes and becomes bad, the goodness remains that made it good. For there is a goodness of which it partook when good; and when it has turned to evil, that goodness continues entire. If the soul fall away and become evil, there is no lessening of goodness; if it return and become good, that goodness is not enlarged. Thine eye participates in this light, and thou seest. Is it shut? Then thou hast not diminished the light. Is it open? Thou hast not increased the light. By this illustration, brethren understand that if the soul is pious, there is piety with God, of which the soul is partaker; if the soul is chaste, there is chastity with God, of which it partakes; if it is good, there is goodness with God, of which it partakes; if it is true, there is truth with God, of which the soul is partaker. Whereof if the soul is no partaker, every man is false; and if every man may be false, no man is true of himself. But the true Father is true of Himself, for He begat the Truth. […]

By reason of the inseparability of the two it was impossible for one of them to be either acknowledged or unknown without the other. "He who sent me," says Jesus, "is true; and I declare to the world what I have heard from him." And the Scripture narrative goes on to explain in a simple way that "they did not understand that he was speaking to them about the Father," although they certainly ought to have known that the Father's words were uttered in the Son, because they read in Jeremiah, "And the Lord said to me, see, I have put my words in your mouth."

"They understood not that He spake to them of the Father." Oh folly! He ceased not to speak concerning Him, and they knew Him not.

"I have many things," He said, "to say of you and to judge: but He that sent me is true;" as if He had said, Therefore I judge the truth, because, as the Son of the True One, I am the truth. The Father true, the Son the truth,-which do we account the greater? Let us reflect, if we can, which is the greater, the True One or the Truth. Take some other instances. Is a pious man, or piety, the more comprehensive? Surely piety itself; for the pious is derived from piety, not piety from the pious. For piety may still exist, though he who was pious became impious. He has lost his piety, but has taken nothing from piety itself. What also of comely and comeliness? Comeliness is more than comely; for comeliness gives existence to the comely, not the comely to comeliness. And so of chaste and chastity. Chastity is clearly something more than chaste. For if chastity had no existence, one would have no ground to be chaste; but though one may refuse to be chaste, chastity remains entire. If then the term piety implies more than the term pious, comeliness more than comely, chastity than chaste, shall we say that the Truth is more than the True One? If we say so, we shall begin to say that the Son is greater than the Father. For the Lord Himself says most distinctly, "I am the way, and the truth, and the life." Therefore, if the Son is the truth, what is the Father but what the Truth Himself says, "He that sent me is true"? The Son is the truth, the Father true. I inquire which is the greater, but find equality. For the true Father is true not because He contained a part of that truth, but because He begat it entire.