4 And what said the Lord to those who savored of the earth? “And He said unto them, You are from beneath.” For this cause ye savor of the earth, because ye lick dust like serpents. You eat earth! What does it mean? You feed on earthly things, you delight in earthly things, you gape after earthly things, you have no heart for what is above. “You are from beneath: I am from above. You are of this world: I am not of this world.” For how could He be of the world, by whom the world was made?
All that are of the world come after the world, because the world preceded; and so man is of the world. But Christ was first, and then the world; and since Christ was before the world, before Christ there was nothing: because “In the beginning was the Word; all things were made by Him.” He, therefore, was of that which is above. But of what that is above? Of the air? Perish the thought! There the birds wing their flight. Of the sky that we see? Again I say, Perish the thought!
It is there that the stars and sun and moon revolve. Of the angels? Neither is this to be understood: by Him who made all things were the angels also made. Of what, then, above is Christ? Of the Father Himself. Nothing is above that God who begot the Word equal with Himself, co-eternal with Himself, only-begotten, timeless, that by Him time's own foundations should be laid. Understand, then, Christ as from above, so as in your thought to get beyond everything that is made—the whole creation together, every material body, every created spirit, everything in any way subject to change: rise above all, as John rose, in order to reach this: “In the beginning was the Word, and the Word was with God, and the Word was God.”
Source: Tractates on the Gospel of John (New Advent)