St. Gregory Thaumaturgus (ca. 213-270, also known as Gregory of Neocaesarea, Gregory of Pontus, Gregory the Wonderworker, or simply The Wonder Worker) is memorialized on November 17. When he become Bishop of Caesarea, there were only 17 Christians. When we died, there were only 17 pagans left in that region. As his name states; there were many Wonder Workings done by the Spirit through Gregory. Saint Gregory of Nyssa said that Gregory of Thaumaturgus was the first person known to receive a vision of the Theotokos (Mary, the Mother of God). In that vision, the Theotokos and the Apostle John gave him a statement of doctrine on the Trinity. That statement is here re-told:
There is One God, the Father of the living Word, who is His subsistent Wisdom and power and Eternal image: perfect Begetter of the perfect Begotten, Father of the only-begotten Son.
The is One Lord, Only of the Only, God of God, Image and Likeness of the Deity, Efficient Word, Wisdom comprehensive of the constitution of all things, and power formative of the whole creation, true Son of true Father, Invisible of Invisible, and Incorruptible of Incorruptible, and Immortal of Immortal and Eternal of Eternal.
And there is One Holy Spirit, having His subsistence from God, and being made manifest by the Son, to wit to men: Image of the Son, Perfect Image of the Perfect Life, the cause of the living; Holy Fount; Sanctity, the Supplier, or Leader, of Sanctification; in whom is manifested God the Father, who is above all and in all, and God the Son, who is through all.
There is a perfect Trinity, in glory and eternity and sovereignty, neither divided nor estranged. Wherefore there is nothing either created or in servitude in the Trinity; nor anything superinduced, as if at some former period it was non-existent, and at some later period it was introduced. And thus neither was the Son ever wanting to the Father, nor the Spirit to the Son; but without variation and without change, the same Trinity abides ever.