Compiled by Issa Haddad

I. Ancient Theology (1st Century-A.D. 590)


From the very beginnings of Christianity the church has always confessed faith in Father, Son, and Holy Spirit. For example, the roots of later Trinitarian thought go back to the doxologies, the benedictions, and the hymnic materials of the primitive church (see 1 Cor 16:23; Phil 2:1-11).

Belief in the Trinity is also affirmed by the early church fathers: Clement (A.D. 30-95) sets forth the equality of the triune God in his statement: “For as God liveth, and the Lord Jesus Christ liveth, and the Holy Spirit, who are the faith and the hope of the elect” (Cor. 58). Athenagoras (A.D. 133-190) provides a clear statement of monotheism and the Trinity. He states: “We acknowledge one God, who is uncreated, eternal, invisible, impassible, incomprehensible, illimitable. He is grasped only by mind and intelligence, and surrounded by light, beauty, spirit, and indescribable power. By him the universe was created through his Word, was set in order, and is held together. (I say ‘his Word’), for we also think that God has a Son” (Athen. Plea 10). Justin Martyr  (A.D. 100-165) gives an interesting statement of the Trinity in saying the Son holds the second place and the prophetic Spirit the third rank (1 Apolo. Just. 13).

The Apostles’ Creed (third-fourth centuries A.D.): “I believe in God the Father Almighty…. And in Jesus Christ his only Son our Lord…. I believe in the Holy Spirit.”

The Council of Nicea – (300 bishops attended) A.D. 325. Because of the Arian controversy,[1] the Council of Nicea met in A.D. 325 to deal with the problem.

The Nicene Creed (A.D. 325; revised at Constantinople A.D. 381): I believe in one God the Father Almighty…. And in one Lord Jesus Christ, the only-begotten Son of God…. And in the Holy Spirit, the Lord and Giver of Life….”

The Chalcedonian Creed (A.D. 451): “We, then, following the holy Fathers, all with one consent, teach men to confess one and the same Son, our Lord Jesus Christ, the same perfect in Godhead and also perfect in manhood; truly God and truly man….”[2]

The Athanasian Creed (fourth-fifth centuries A.D.): “We worship one God in Trinity, and Trinity in Unity; neither confounding the Persons: nor dividing the Substance. For there is one Person of the Father: another of the Son: and another of the Holy Spirit. But the Godhead of the Father, of the Son, and of the Holy Spirit, is all one: the Glory equal, the Majesty coeternal.”

II. Medieval Theology (A.D. 590-1517)


The medieval doctrine of God stands on the shoulders of the ancient affirmation of God’s oneness and threeness. No medieval scholar would deny what was affirmed in the early church and reiterated in the Fourth Lateran Council (1215): “We firmly believe and profess without qualification that there is only one true God, eternal, immense, unchangeable, incomprehensible, omnipotent, and indescribable, the Father, the Son, and the Holy Spirit; three persons but one essence, substance or nature that is wholly simple.” The dogma of the Trinity was set. No debates about the Trinity appear in the medieval era.

III. Reformation Theology (1517-1750)


The Protestant churches, sharing so richly in the heritage of the Catholic Church, did not diverge from their Roman Catholic opponents in understanding the Trinity. Though Martin Luther (1483-1546) believed that Trinitarian comprehension is beyond the grasp of natural, rational faculties, he wrote:

Scriptures…cleverly prove that there are three persons and one God. For I would believe neither the writings of Augustine nor the teachers of the church unless the New and Old Testaments clearly show this doctrine of the Trinity. (Works 39.289)

The Augsburg Confession (1530), a marvelous expression of Lutheran orthodoxy, stated the Trinity beautifully: “The churches, with common consent among us, do teach that the decree of the Nicene Synod concerning the unity of the divine essence and the three persons is true, and without doubt to be believed” (Article I).

John Calvin commenting on Paul’s phrase that Christ is the “brightness of His glory,” Calvin wrote:

The fair inference from the Apostle’s words is, that there is a proper subsistence of the Father which shines refulgent in the Son. From this, again, it is easy to infer that there is a subsistence of the Son which distinguishes him from the Father. The same holds in the case of the Holy Spirit; for we will immediately prove both that he is God, and that he has a separate substance from the Father (I.13.2) (Book I of the Institutes of the Christian Religion).

IV. Modern Theology (1750-present)

A. H. Strong: “In the nature of the one God there are three eternal distinctions which are represented to us under the figure of persons, and these three are equal.” (Systematic Theology, p. 304)

Millard Erickson: “A reference to the doctrine that God is one and yet exists eternally in three persons.” 

Wayne Grudem: “God eternally exists as three persons, Father, Son, and Holy Spirit, and each person is fully God, and there is one God.”

James R. White: “Within the one Being that is God, there exists eternally three coequal and coeternal persons, namely, the Father, the Son, and the Holy Spirit. (The Forgotten Trinity, p. 26)

 Westminster Confession of Faith (1643-46) – (from John Calvin): “There is but one only, living, and true God, who is infinite in being and perfection, a most pure spirit… In the unity of the Godhead there be three persons, of one substance, power, and eternity: God the Father, God the Son, and God the Holy Ghost.”

The London Baptist Confession of Faith (1677/89): The Lord our God is but one only living and true God; whose subsistence is in and of himself; infinite in being and perfection; whose essence cannot be comprehended by any but himself…. In this divine and infinite Being there are three subsistences, the Father, the Word or Son, and Holy Spirit, of one substance, power, and eternity, each having the whole divine essence, yet the essence undivided….”

The New Hampshire Baptist Confession (1833): “We believe that there is one, and only one, living and true God…that in the unity of the Godhead there are three persons, the Father, the Son and the Holy Spirit; equal in every divine perfection, and executing distinct and harmonious offices in the great work of redemption.

Baptist Faith and Message (Southern Baptist Convention, 1925, revised 1963): “There is one and only one living and true God…. The eternal God reveals Himself to us as Father, Son, and Holy Spirit, with distinct personal attributes, but without division of nature, essence, or being.”

[1]The most prominent name in the Trinitarian controversy is Arius, a presbyter of Alexandria. In opposition to modalistic monarchianism, Arius taught that only one who is called God is eternal and, in fact, is incomprehensible. To suggest that Christ is eternal would be to affirm two Gods.

Arius was opposed by the highly capable Athanasius of Alexandria. Athanasius stressed the oneness of God while maintaining three distinct Persons within the Godhead.

[2]At the time of the Chalcedonian Creed it seems like the problem the church was facing is the reality of Christ’s divinity and manhood. As it is look from reading the confession the emphasis is on the Lord Jesus and the controversy between his divinity and manhood.