Continuing our week of Creeds, we come to Tertullian,
“Now, with regard to this rule of faith-that we may from this point acknowledge what it is which we defend-it is, you must know, that which prescribes the belief that there is one only God, and that He is none other than the Creator of the world, who produced all things out of nothing through His own Word, first of all sent forth; that this Word is called His Son, and, under the name of God, was seen “in diverse manners” by the patriarchs, heard at all times in the prophets, at last brought down by the Spirit and Power of the Father into the Virgin Mary, was made flesh in her womb, and, being born of her, went forth as Jesus Christ; thenceforth He preached the new law and the new promise of the kingdom of heaven, worked miracles; having been crucified, He rose again the third day; (then) having ascended into the heavens, He sat at the right hand of the Father; sent instead of Himself the Power of the Holy Ghost to lead such as believe; will come with glory to take the saints to the enjoyment of everlasting life and of the heavenly promises, and to condemn the wicked to everlasting fire, after the resurrection of both these classes shall have happened, together with the restoration of their flesh. This rule, as it will be proved, was taught by Christ, and raises amongst ourselves no other questions than those which heresies introduce, and which make men heretics.” (Tertullian, the Prescription Against Heretics, Chapter XIII)
Tertullian stands somewhere past Irenaeus in development, but before Nicaea. For Tertullian, the Godhead was not yet ontological, but still somewhat economic. There is but one God and Creator who sent out both the Word and the Spirit (and Power). The Word becomes the Son and survives under the name of ‘God’ during different ways of being seen by the Jews, but it was not until the Incarnation that the Word was ‘brought down’ and made flesh in the womb of the Virgin. This is similiar to Marcellus’ understanding of the Preincarnate and the Incarnate. Further, this same Jesus Christ sent the Power of the Spirit.
“”With whom lies that very faith to which the Scriptures belong. From what and through whom, and when, and to whom, has been handed down that rule, by which men become Christians?” For wherever it shall be manifest that the true Christian rule and faith shall be, there will likewise be the true Scriptures and expositions thereof, and all the Christian traditions. (Tertullian, The prescription against the heretics, Ch 19)