Tertullian — Against Praxeas 5
Well, but the nations , who are strangers to all understanding of spiritual powers, ascribe to their idols the imbuing of waters with the self-same efficacy. (So they do) but they cheat themselves with waters which are widowed. For washing is the channel through which they are initiated into some sacred rites — of some notorious Isis or Mithras . The gods themselves likewise they honour by washings. Moreover, by carrying water around, and sprinkling it, they everywhere expiate country-seats, houses, temples, and whole cities: at all events, at the Apollinarian and Eleusinian games they are baptized ; and they presume that the effect of their doing that is their regeneration and the remission of the penalties due to their perjuries .
Among the ancients, again, whoever had defiled himself with murder , was wont to go in quest of purifying waters. Therefore, if the mere nature of water, in that it is the appropriate material for washing away, leads men to flatter themselves with a belief in omens of purification, how much more truly will waters render that service through the authority of God , by whom all their nature has been constituted! If men think that water is endued with a medicinal virtue by religion, what religion is more effectual than that of the living God? Which fact being acknowledged, we recognise here also the zeal of the devil rivalling the things of God , while we find him, too, practising baptism in his subjects . What similarity is there? The unclean cleanses! The ruiner sets free! The damned absolves!
He will, forsooth, destroy his own work, by washing away the sins which himself inspires! These (remarks) have been set down by way of testimony against such as reject the faith ; if they put no trust in the things of God , the spurious imitations of which, in the case of God's rival, they do trust in. Are there not other cases too, in which, without any sacrament, unclean spirits brood on waters, in spurious imitation of that brooding of the Divine Spirit in the very beginning? Witness all shady founts, and all unfrequented brooks, and the ponds in the baths, and the conduits in private houses, or the cisterns and wells which are said to have the property of spiriting away, through the power, that is, of a hurtful spirit.
Men whom waters have drowned or affected with madness or with fear , they call nymph-caught, or lymphatic, or hydro-phobic. Why have we adduced these instances? Lest any think it too hard for belief that a holy angel of God should grant his presence to waters, to temper them to man's salvation ; while the evil angel holds frequent profane commerce with the selfsame element to man's ruin. If it seems a novelty for an angel to be present in waters, an example of what was to come to pass has forerun. An angel , by his intervention, was wont to stir the pool at Bethsaida . They who were complaining of ill-health used to watch for him; for whoever had been the first to descend into them, after his washing, ceased to complain.