Tertullian · a new plain-English translation from the original language
[1] It will suffice, though, to have skimmed off enough here that the reasoning of baptism can also be recognized in that first thing which even by its very posture was already prefiguring the shape of baptism: the Spirit of God, who from the beginning was borne above the waters, was to abide above the waters of him who does the baptizing. Now what is holy was of course being borne above what is holy — or rather, from the very fact of being borne above, that which was borne beneath was on loan for holiness from it, since whatever underlying matter necessarily seizes upon the quality of what hovers over it, especially when a bodily thing is easily penetrated and settled into by a spiritual one, through the fineness of its substance. Thus the nature of the waters, sanctified from what is holy, itself conceived the power to sanctify. [2] Let no one say, then, 'Surely we are not baptized in those very waters which existed back then at the beginning?' Not in those very ones, no — except insofar as, though the genus is one, the species are many. And what is attributed to the genus overflows into the species as well. [3] And so there is no distinction whether one is washed in sea or pond, river or spring, lake or channel, nor is there any difference between those whom John dipped in the Jordan and those whom Peter dipped in the Tiber — unless perhaps that eunuch too, whom Philip dipped in some chance water found along the road, brought back more or less salvation for it. [4] So then, all waters, by the ancient privilege of their origin, attain the sacrament of sanctification once God is invoked. For the Spirit at once comes down from the heavens and settles upon the waters, sanctifying them from himself, and thus sanctified, they drink in the power of sanctifying. [5] And yet a certain likeness fits the simple act as well: since we are stained by sins the way one is stained by dirt, we are washed clean by waters. But just as sins do not show on the flesh — no one carries on his skin a smear of idolatry, or fornication, or fraud — so too such things are grime upon the soul, whose will originates the wrongdoing: for the soul commands, the flesh obeys. Yet the two share the guilt between them, the spirit for the command, the flesh for the carrying-out. And so, the waters being in a manner medicated by the angel's intervention, the spirit is washed clean bodily in the water, and the flesh is cleansed spiritually in that same water.