The Faith of Lucifer and the Faith of Faustinus

The faith written against the Arian heresy would have sufficed. But since certain persons, with depraved intent, under the profession of that faith change the impious words, bringing odium upon us, as though we upheld the heresy of Sabellius; in a few words we mark also, against Sabellius, a confession of the primal faith; and against those who, under the name of the catholic faith, defend impious words, saying that there are three substances; whereas the catholic faith has always confessed one substance of the Father and the Son and the Holy Spirit.

We believe the Father, who is not the Son, but who has a Son begotten of himself without beginning, not made: and we believe the Son, who is not the Father, but who has a Father, of whom he was begotten, not made: and we believe the Holy Spirit, who is truly the Spirit of God. Wherefore we also confess one substance of the divine Trinity: because such as the Father is according to substance, such did he beget the Son also: and the Holy Spirit, not existing as a creature, but being the Spirit of God, is not alien from the substance of the Father and the Son; but is himself of the same substance with the Father and the Son, as of the same Godhead.

For as for those who think us to be Apollinarists, let them know that we abhor the heresy of Apollinaris no less than the Arian. But we marvel that those can be proved catholics who confess three substances of the Father, and the Son, and the Holy Spirit. But even if they say that they do not believe the Son of God, or the Holy Spirit, to be a creature; nevertheless they hold a view that runs impiously counter to the faith, when they say that there are three substances: for it follows that those who confess three substances must confess three Gods. Which expression the catholics have always abhorred.