Tertullian, On Baptism 5
Foreign nations, completely lacking any grasp of spiritual realities, nevertheless claim the same power for their idols, yet they only cheat themselves with empty water. They even initiate people into certain sacred rites through washing — whether for Isis or Mithras — and they parade their own gods in processions accompanied by washings. Besides that, they sprinkle water everywhere around villas, homes, temples, and whole cities to purify them, and they certainly get drenched at the Apollinarian and Eleusinian games. They presume that by doing this they are regenerated and freed from punishment for their perjuries. Likewise, among the ancients, anyone who had defiled himself with homicide would purify himself with cleansing water. So if they boast about water's natural power — since its very substance serves as the material for cleansing in rites of purification — how much more truly will water provide this through God's authority, by whom all nature was established? If they think water is sanctified by religion, what religion is more powerful than that of the living God? Recognizing this, we also recognize here the devil's strategy, since he emulates the things of God, even practicing baptism among his own followers. What a resemblance: the unclean one cleanses, the destroyer liberates, the condemned one absolves. He will certainly destroy his own work, washing away the very sins he himself inspires. These things are set forth as testimony for those who reject the faith, if they refuse to believe the things of God, whose counterfeits they trust in the emulator of God. Do not unclean spirits also, without any sacrament, brood in waters, mimicking that primordial gestation of the divine Spirit? Everyone knows the dark springs, the remote streams, the pools in baths, the channels in houses or cisterns, and the wells said to be seized — certainly by the force of a harmful spirit. For they call those who have been drowned, or driven mad, or afflicted with hydrophobia — whom the waters have killed or tormented with madness or fear. Why have we recounted these things? So that no one may think it strange that the holy Angel of God is present in the waters, tempering them for human salvation, when the evil angel frequently engages in profane commerce with the same element to humanity's destruction. If it seems new that an angel intervenes in the waters, the example of the future precedes it. An Angel intervened at the pool of Bethsaida, stirring it; those seeking health watched for it. For if anyone managed to go down first, he would cease complaining after washing (John 5:4). This figure of physical medicine proclaimed spiritual medicine, in the pattern where carnal things always prefigure spiritual ones. Therefore, as God's grace advanced among men, more was added to the waters and the Angel: those who once remedied bodily diseases now heal the spirit; those who worked temporal salvation now reform eternal salvation; those who freed one person once a year now daily preserve whole peoples, death having been abolished through the washing away of sins. Certainly, with the guilt removed, the penalty is also removed. Thus man is restored to God in His likeness, he who was formerly in the image of God; the image is reckoned in the likeness, the likeness in eternity. For he receives the Spirit of God, which he had once received from God's breath, but later lost through sin.
Latin
Sed enim nationes extraneae ab omni intellectu spiritalium potestatem eadem efficacia idolis suis subministrant, sed, viduis aquis, sibi mentiuntur. Nam et sacris quibusdam per lavacrum initiantur, Isidis alicujus, aut Mithrae, ipsos etiam deos suos lavationibus efferunt. Caeterum villas, domos, templa totasque urbes aspergine circumlatae aquae expiant passim, certe ludis Apollinaribus et Eleusiniis tinguntur. Idque se in regenerationem et impunitatem perjuriorum suorum agere praesumunt. Item penes veteres quisquis se homicidio infecerat, purgatrice aqua se expiebat. Igitur si de sola natura aquis, quod propria materia sit abluendi in auspicia emundationis, blandiuntur, quanto id verius aquae praestabunt per Dei auctoritatem, a quo omnis natura earum constituta est? Si religione aquam medicari putant, quae potior religio, quam Dei vivi? quo agnito, hic quoque studium diaboli recognoscimus res Dei aemulantis, cum et ipse Baptismum in suis exercet. Quid simile? Immundus emundat, perditor liberat, damnatus absolvit. Suam videlicet operam destruet, diluens delicta quae inspirat ipse. Haec quidem in testimonium posita sunt repellentibus fidem, si minime credant rebus Dei, quarum affectationibus apud aemulum Dei credunt. Annon et alias sine ullo sacramento immundi spiritus aquis incubant, adfectantes illam in primordio divini spiritus gestationem? Sciunt opaci quique fontes, et avii quique rivi, et in balneis piscinae, et euripi in domibus vel cisternae, et putei, qui rapere dicuntur, scilicet per vim spiritus nocentis. Nam et enectos et lymphatos et hydrophobos vocant, quos aquae necaverunt, aut amentia vel formidine exercuerunt. Quorsum ista retulimus? Ne quis durius credat Angelum Dei sanctum aquis in salutem hominis temperandis adesse, cum Angelus malus profanum commercium ejusdem elementi in perniciem hominis frequentet. Angelum aquis intervenire si novum videtur, exemplum futuri praecucurrit. Piscinam Bethsaidam Angelus interveniens commovebat; observabant qui valetudinem querebantur. Nam si quis praevenerat descendere illuc, queri post lavacrum desinebat. Figura ista medicinae corporalis spiritalem medicinam canebat, ea forma, qua semper carnalia in figura spiritalium antecedunt. Proficiente itaque in hominibus gratia Dei, plus aquis et Angelo accessit: qui vitia corporis remediabant, nunc spiritum medentur: qui temporalem operabantur salutem, nunc aeternam reformant: qui unum semel anno liberabant, nunc quotidie populos conservant, deleta morte per ablutionem delictorum. Exempto scilicet reatu, eximitur et poena. Ita restituitur homo Deo ad similitudinem ejus, qui retro ad imaginem Dei fuerat; imago in effigie, similitudo in aeternitate censetur. Recipit enim illum Dei spiritum, quem tunc de afflatu ejus acceperat, sed post amiserat per delictum.