Tertullian · a new plain-English translation from the original language
[1] And so, in their scheme, in due course the Father came to birth and the Father endured suffering — he himself, God, the Almighty Lord, is announced as Jesus Christ. We, however — both always, and now more fully, being better instructed through the Paraclete, that guide into all truth — believe in one God only, but under the following administration, which we call the oikonomia: that the one God also has a Son, his Word, who proceeded from him, by whom all things came to be and apart from whom nothing came into being; that this Word was sent by the Father into a virgin and was born of her, man and God, Son of Man and Son of God, and was named Jesus Christ; that he suffered, died, and was buried according to the scriptures, and was raised up by the Father and taken back into heaven, where he sits at the right hand of the Father, and will come to judge the living and the dead; and that from there, according to his promise, he sent forth from the Father the Holy Spirit, the Advocate, who sanctifies the trust of all who put faith in the Father, the Son, and the Holy Spirit. [2] That this rule has run down from the very beginning of the gospel — even before any earlier heretics, let alone before yesterday's Praxeas — will be proved both by the sheer lateness of all heretics and by the sheer novelty of yesterday's Praxeas. By this rule, equally applicable against every heresy, it has already been settled in advance that whatever is first is true, and whatever comes later is a corruption. [3] But even with that principle safely in place, room must still be left everywhere, for the sake of instructing and fortifying certain people, for further discussion — if only so that no particular error should seem to be condemned without a hearing rather than simply prejudged, especially this one, which imagines it alone possesses the plain truth, on the ground that it will not believe in the one God unless it can say that the very same being is Father, Son, and Holy Spirit all at once: [4] as though he were not, in this very sense, still one — since all things come from one — through unity of substance, and the mystery of the oikonomia is nonetheless still preserved, which arranges the unity into a trinity, setting forth Father, Son, and Spirit as three — three, yet not in condition but in sequence, not in essence but in appearance, not in might but in aspect — though of a single essence, a single condition, and a single might, since it is one God from whom these degrees, forms, and aspects are reckoned under the names of Father, Son, and Holy Spirit. How they admit of number without division, the discussion that follows will show.