Tractates on the Gospel of John

⁴ The Jews then answered, “You bear witness of yourself; your witness is not true.” Let us see what they hear; let us also hear, yet not as they did: they despising, we believing; they wishing to slay Christ, we desiring to live through Christ. Let this difference distinguish our ears and minds from theirs, and let us hear what the Lord answers to the Jews. “Jesus answered and said to them, Though I bear witness of myself, my witness is true; because I know whence I came and whither I go.”

The light shows both other things and also itself. Thou lightest a lamp, for instance, to look for your coat, and the burning lamp affords you light to find your coat; do you light the lamp to see itself when it burns? A burning lamp is indeed capable at the same time of exposing to view other things which the darkness covered, and also of showing itself to your eyes. So also the Lord Christ distinguished between His faithful ones and His Jewish enemies, as between light and darkness: as between those whom He illuminated with the ray of faith, and those on whose closed eyes He shed His light.

So, too, the sun shines on the face of the sighted and of the blind; both alike standing and facing the sun are shone upon in the flesh, but both are not enlightened in the eyesight. The one sees, the other sees not: the sun is present to both, but one is absent from the present sun. So likewise the Wisdom of God, the Word of God, the Lord Jesus Christ, is everywhere present, because the truth is everywhere, wisdom is everywhere. One man in the east understands justice, another man in the west understands justice; is justice which the one understands a different thing from that which the other understands?

In body they are far apart, and yet they have the eyes of their minds on one object. The justice which I, placed here, see, if justice it is, is the same which the just man, separated from me in the flesh by ever so many days' journey, also sees, and is united to me in the light of that justice. Therefore the light bears witness to itself; it opens the sound eyes and is its own witness, that it may be known as the light. But how about the unbelievers? Is it not present to them?

It is present also to them, but they have not eyes of the heart with which to see it. Hear the sentence fetched from the Gospel itself concerning them: “And the light shines in darkness, and the darkness comprehended it not.” Hence the Lord says, and says truly, “Though I bear witness of myself, my witness is true; because I know whence I came and whither I go.” He meant us to understand the Father here: the Son gave glory to the Father. Himself the equal glorifies Him by whom He was sent. How ought man to glorify Him by whom he was created!