The Father is called source and light: “They have abandoned me, the source of living water.” And in Baruch, “How is it, Israel, that you are in the land of your enemies? You have abandoned the source of wisdom.” And according to John, “Our God is light.” The Son, in relation to the source, is called a river: “The river of God is full of waters.” In relation to light, he is called splendor, as Paul says, “He is the splendor of the glory and the imprint of his being.” The Father is thus light and the Son his splendor (we need not fear repeating the same things often, especially in these matters). Now, it is possible to see in the Son also the Spirit, in whom we are enlightened, “that he would give you,” it is said, “the Spirit of wisdom and of revelation, in the knowledge of him, by enlightening the eyes of the heart.” Enlightened then by the Spirit, it is Christ who enlightens in him. It is said, in fact, that “he was the true light that enlightens every person who comes into the world.” Analogously, then, if the Father is the source and the Son is called river, we drink of the Spirit, as it is written, “We have all been given to drink of the one Spirit.” But, at the same time, drinking of the Spirit we drink of Christ: “They drank from the spiritual rock that followed them, and the rock was Christ.”
