Tractates on the Gospel of John

^4. The Lord, therefore, cries aloud to us to come and drink, if we thirst within; and He says that when we have drunk, rivers of living water shall flow from our belly. The belly of the inner man is the conscience of the heart. Having drunk that water then, the conscience being purged begins to live; and drinking in, it will have a fountain, will be itself a fountain. What is the fountain, and what the river that flows from the belly of the inner man? Benevolence, whereby a man will consult the interest of his neighbor. For if he imagines that what he drinks ought to be only for his own satisfying, there is no flowing of living water from his belly; but if he is quick to consult for the good of his neighbor, then he becomes not dry, because there is a flowing. We will now see what it is that they drink who believe in the Lord; because we surely are Christians, and if we believe, we drink. And it is every man's duty to know in himself whether or not he drinks, and whether he lives by what he drinks; for the fountain does not forsake us if we forsake not the fountain.