On earth, a fountain is one thing, light another. When you are thirsty, you look for a fountain, and to get to the fountain you look for light; and if there is no daylight, you light a lamp to get to the fountain. But He is both a fountain and a light: to the thirsty he is a fountain, to the blind a light. Let [your] eyes be opened to see the light; let the lips of [your] heart be opened to drink of the fountain. That which you drink, you see and hear. God becomes everything to you, for He is the whole of the things you love. If you attend to visible things, well, God is neither bread nor is He water, nor light, nor a garment, nor a house. For all these things are visible, individual, and separate. What bread is, water is not; what a garment is, a house is not; and what these things are, God is not, for they are visible things. God is all of these things to you: if you are hungry, he is bread to you; if you are thirsty, He is water to you; if you live in darkness, he is light to you, for he remains incorruptible. If you are naked, He is a garment of immortality to you when this corruptible shall put on incorruption and this mortal shall put on immortality.
– Augustine, Lectures on the Gospel of John, tract. 13.5 (on John 3:22-29)