The Earliest Mention of the “Trinity”

The word “Trinity” is not found in the Bible, but it is a technical term for a biblical teaching. When was the term “Trinity” first used?

Tertullian

The Latin Christian Tertullian is popularly credited with coining the term “Trinity”. Indeed, he is the earliest known writer to use the Latin word trinitas, which is where the English word “Trinity” originated:

Quid nunc et ad ecclesiam et quidem tuam, psychice? Secundum enim Petri personam spiritalibus potestas ista conueniet, aut apostolo aut prophetae. Nam et ipsa ecclesia proprie et principaliter ipse est spiritus, in quo est trinitas unius diuinitatis, Pater et Filius et Spiritus sanctus. Illam ecclesiam congregat quam Dominus in tribus posuit.

What now is it to the church and to your church indeed, O psychic? For, according to the person of Peter, that power will convene with spiritual people, either an apostle or a prophet. For the church itself also, properly and principally, is the spirit itself, in which is the Trinity [trinitas] of one divinity, the Father, the Son, and the Holy Spirit. It congregates that church which the Lord put in three. — Tertullian, De Pudicitia 21.16.

Theophilus of Antioch

However, the earliest use of a term to refer to the triunity of God is actually by Theophilus of Antioch, who beat Tertullian to it by at least 20 years. Because Theophilus wrote in Greek, he did not use the Latin word trinitas, but the Greek word trias (τριάς). Here is the earliest known mention of the “Trinity” in Christian History:

Ὡσαύτως καὶ αἱ τρεῖς ἡμέραι πρὸ τῶν φωστήρων γεγονυῖαι τύποι εἰσὶν τῆς τριάδος, τοῦ θεοῦ καὶ τοῦ λόγου αὐτοῦ καὶ τῆς σοφίας αὐτοῦ. τετάρτῳ δὲ τόπῳ ἐστὶν ἄνθρωπος ὁ προσδεὴς τοῦ φωτός, ἵνα ᾖ θεός, λόγος, σοφία, ἄνθρωπος. διὰ τοῦτο καὶ τετάρτῃ ἡμέρᾳ ἐγενήθησαν φωστῆρες.

Likewise also the three days which had come to pass before the luminaries are types of the Trinity [τριάς], of God, and of his word, and of his wisdom. In the fourth place is man, the needer of the light, so that it may be God, word, wisdom, man. Because of this also on the fourth day the luminaries were made. — Theophilus of Antioch, To Autolychus 2.15.