When it comes to Christian doctrine, nearly everyone knows of importance of the doctrine of the Trinity. And yet, not everyone is equally aware that throughout history, and throughout different parts of the church, the doctrine of the Trinity has been understood in various different ways. “Classical Trinitarianism” is the term I use to refer to the doctrine of the Trinity as articulated by the orthodox church fathers who lived both prior to and during the time of the Council of Nicea. This understanding of the doctrine of the Trinity is faithfully set forth in the writings of such church fathers as Justin Martyr, Irenaeus of Lyons, Cyril of Jerusalem, those assembled at the Council of Antioch in 345, and those assembled at the Councils of Arminium and Seleucia in 359.
Classical trinitarianism can be summed up as teaching that there are three (and only three) distinct and inseparable divine persons, each sharing the same eternity: the one God, the Father Almighty, His only-begotten Son, the Lord Jesus Christ, and His Holy Spirit.
This is the most ancient articulation of the doctrine of the Trinity the church has, dating back to an era before the politics of the Roman government played a major role in the doctrinal positions of the churches, to a time when the teaching of the apostles was still ringing freshly in the ears of their students, the first generation of church fathers.
While this view can be historically established as the ancient view of Christianity received by tradition from the apostles, far more importantly this understanding of the doctrine of the Trinity entirely biblical. Every part of it can be proven from the holy and infallible scriptures, and unlike many later articulations that describe the Trinity in unbiblical terms, or add things to the doctrine of the Trinity which cannot be found in scripture, classical trinitarianism simply says what the scriptures say about the persons of God, His only-begotten Son, and His Holy Spirit.
Many rival formulations of the doctrine of the Trinity make the issues involved extremely complex, philosophical, esoteric, and paradoxical. While certainly some aspects of the doctrine of the Trinity are beyond our comprehension, the scriptural doctrine of the Trinity is far less complicated and confusing than many theologians have made it out to be.
Following the great commission given in Matthew 28, and the apostle Paul’s summary of what unites Christians in Ephesians 4:4-6, the biblical doctrine of the Trinity can be summed up as “Father, Son, and Holy Spirit” and “one Spirit… one Lord… and one God and Father Who is over all and through all and in all.” Similarly we receive a beautiful symbolic picture of the Trinity in Revelation chapters 4-5, which describe “the Lord God Almighty” seated on His throne, “the Lamb” of God standing at His right hand, and the “Spirit of God” pictured before the throne of God as the fire of seven lamps burning.
What we see from each of these passages is that the doctrine of the Trinity is ultimately the doctrine of what we believe about three persons: the one God, the Father Almighty, His only-begotten Son, Jesus Christ the Lord, and His Holy Spirit, the Paraclete. Thus the ancient Creeds of the church have delivered the doctrine of the Christian faith as summed up in three points, firstly, pertaining to the “one God”, the Father, the Almighty, secondly, pertaining to His Son, Who is His eternal Word and Wisdom, begotten of Him before time, Who took on a human nature and came to earth for our salvation in the incarnation, and thirdly, pertaining to the Holy Spirit, with Whom believers are sealed.
Thus we see one of the earliest summaries of Christian doctrine from Irenaeus of Lyons sums up the Christian faith:
“This then is the order of the rule of our faith, and the foundation of the building, and the stability of our conversation: God, the Father, not made, not material, invisible; one God, the creator of all things: this is the first point of our faith. The second point is: The Word of God, Son of God, Christ Jesus our Lord, who was manifested to the prophets according to the form of their prophesying and according to the method of the dispensation of the Father: through whom all things were made; who also at the end of the times, to complete and gather up all things, was made man among men, visible and tangible, in order to abolish death and show forth life and produce a community of union between God and man. And the third point is: The Holy Spirit, through whom the prophets prophesied, and the fathers learned the things of God, and the righteous were led forth into the way of righteousness; and who in the end of the times was poured out in a new way upon mankind in all the earth, renewing man unto God.” (Irenaeus, Demonstration of the Apostolic Preaching)
We can also observe the same structure in the ancient baptismal Creeds of the church, which served as local summaries of Christian doctrine for new converts to recite at their baptism. The baptismal Creed of Jerusalem read:
“I believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible;
And in one Lord Jesus Christ, the only begotten Son of God, begotten of the Father before the ages, true God, by whom all things were made, who was incarnate and made man, crucified and buried, and the third day ascended into the heavens, and sat down at the right hand of the Father, and is coming to judge quick and dead.
And in the Holy Ghost, the Paraclete, who spake by the prophets;
And in one holy catholic Church; and resurrection of the flesh; and in life everlasting.”
Finally the ‘Homoian Creed’ of Arminium and Seleucia is structured in fundamentally the same way, following the pattern set in scripture in Ephesians 4:4-6 and 1 Corinthians 8:6, saying:
“We believe in one only true God, the Father Almighty, of whom are all things.
And in the only-begotten Son of God, who before all ages and before every beginning was begotten of God, through whom all things were made, both visible and invisible; alone begotten, only-begotten of the Father alone, God of God; like the Father that begat Him, according to the Scriptures, whose generation no one knows except only the Father that begat Him. This only-begotten Son of God, sent by His Father, we know to have come down from heaven, as it is written, for the destruction of sin and death; begotten of the Holy Ghost and the virgin Mary, as it is written, according to the flesh. Who companied with His disciples, and when the dispensation was fulfilled, according to the Father’s will, was crucified, died and was buried, and descended to the world below, at whom Hell himself trembled. On the third day He rose from the dead and companied with His disciples forty days. He was taken up into Heaven, and sits on the right hand of His Father, and is coming at the last day of the Resurrection, in His Father’s glory, to render to everyone according to his works.
And we believe in the Holy Ghost, which the only-begotten Son of God, Jesus Christ, both God and Lord, promised to send to man, the Comforter, as it is written, the Spirit of Truth. This Spirit He Himself sent after He had ascended into Heaven and sat at the right hand of the Father, from there to come to judge both the living and the dead.
But the word ‘substance,’ which was too simply inserted by the Fathers, and, not being understood by the people, was a cause of scandal through its not being found in the Scriptures, it has seemed good to us to remove, and that for the future no mention whatever be permitted of the ‘substance’ of the Father and the Son. Nor must one ‘essence’ be named in relation to the person of Father, Son, and Holy Ghost. And we call the Son like the Father, as the Holy Scriptures call Him and teach; but all the heresies, both those already condemned, and any, if such there be, which have risen against the document thus put forth, let them be anathema.”
All these summaries of faith are clear on several important points of trinitarian doctrine, identifying each person of the Trinity in the way the scriptures describe Them. The Father is the one God, the Almighty; the Son is our one Lord, only-begotten of the Father before all time, thus being a distinct person from the Father Who is co-eternal with Him, Who is also God and Lord, as sharing in the Father’s authority and dominion the universe. Likewise the Holy Spirit of God is identified as a third distinct person, God’s Spirit.
Yet these statements of faith, while wholly biblical, can leave us with some questions: Why is the Father identified as the “one God”, when the Son is also taught to be “God of God”, sharing the same divinity as the Father? And while each person of the Trinity is identified distinctly in these statements, in what sense are these three persons “one”?
The answers to these questions are ultimately not as mysterious and paradoxical as heretics or Latin medieval scholastics would have you believe.
The early church fathers taught that there was only one God because there is only one supreme uncaused Cause of all things, the one supreme authority over all things, the person of the Father. Whereas the Son is described by scripture as eternally “begotten” of the Father, and the Spirit as eternal and “proceeding” from Him, the Father simply is, existing as He is without any cause or origin whatsoever. He Himself is the Cause not only of all creation, but also of His own Son and Holy Spirit through Whom He made all things. Likewise, the Father alone is the Supreme Authority over all absolutely, having authority over not only over all creation, but also over His own Son and Holy Spirit. For scriptural proof and patristic quotes on these topics, see Why There is Only One God: One Supreme Cause and Why There is Only One God: Headship.
The three persons of the Trinity are never explicitly described as being “one” anywhere in scripture; the one verse that says that has been nearly universally recognised as a later interpolation of the text, and does not appear in most Bibles. Even so, the sense of that verse is the same as other passages of scripture, which teach that the Father and Son are “one”. A cursory examination of the passages quickly reveals their meaning: most of them speak of the perfect agreement between the persons, in which respect they are “one” in will and mind, just as many individual believers in the book of Acts are described as being of “one mind” (Acts 2:46) and “one heart and soul” (Acts 4:32):
“Now I am no longer in the world, but these are in the world, and I come to You. Holy Father, keep through Your name those whom You have given Me, that they may be one as We are… that they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me.” (John 17:11, 21 NKJV)
So we see then that the close relational unity of the persons, and the perfect agreement They share, is spoken of as unity, a unity that believers are said to be able to share in. While this unity between God, His Son, and His Spirit includes this unity of perfect agreement, it extends beyond that; the persons are described by scripture as mutually indwelling each other, and being inseparable from each other. Thus John 1:18 says “No one has seen God at any time. The only begotten Son, who is in the bosom of the Father, He has declared Him.”(NKJV). The Son, then, is eternally in the bosom of the Father, distinct from Him, and yet inseparable from Him.
Related to this inseparability of the persons, we often see in scripture that God works though His Son and Holy Spirit. In the creation, sustenance, redemption, and the judgement of the world, scripture tells us that God works through His Son and Holy Spirit.
We also read in the scriptures that the Son is the “Image of the invisible God”, to Whom the Father said in the beginning “Let us make man in Our Image, after Our likeness”. So God and His Son are revealed to share a common image and likeness, as They also are revealed to share one will, one kingdom, one divinity, one Spirit, and to be united in Their actions.
For a more detailed explanation of what it means that the Son is God, sharing in His Father’s divinity, see The Meaning of the Term ‘God’.
We see, then, that the answers to these questions are not beyond the scope of what God has revealed to us in the scriptures. There is one God because the Father is one (Who alone is called by scripture the “one God” and “only God”). The Father alone is the supreme uncaused Cause of all and Supreme Authority over all (the idea carried by the Greek word often translated “Almighty”, Pantokrator). His Son and Holy Spirit, however, are united with Him, or one with Him, in the close unity that the persons share in action and in will.
To conclude this introduction to classical trinitarianism, let us close with the Creed composed at Antioch in 345, known as the Macrostich (or “long-lined creed”). This ancient Creed includes a great deal of detail, proclaiming the truth of classical trinitarianism and providing detailed explanations of the points of doctrine it confesses, and carefully distinguishing classical trinitarianism from the various heresies, specifically rejecting Arianism, Modalism, and Tritheism:
“We believe in one God, the Father Almighty, the Creator and Maker of all things, from whom all fatherhood in heaven and on earth is named.
And in His Only-begotten Son our Lord Jesus Christ, who before all ages was begotten from the Father, God from God, Light from Light, by whom all things were made, in heaven and on the earth, visible and invisible, being Word and Wisdom and Power and Life and True Light, who in the last days was made man for us, and was born of the Holy Virgin, crucified and died and was buried, and rose again from the dead on the third day, and was taken up into heaven, and sat down on the right hand of the Father, and is coming at the consummation of the age to judge the living and the dead, and to render to everyone according to his works; whose kingdom endures unceasingly unto all the ages; for He sits on the right hand of the Father, not only in this age, but also in that which is to come.
And we believe in the Holy Ghost, that is, the Paraclete, which, having promised to the apostles, He sent forth after the ascension into heaven, to teach them and to remind of all things; through whom also shall be sanctified the souls of those who sincerely believe in Him.
But those who say that the Son was from nothing, or from other subsistence and not from God; and that there was a time or age when He was not, the catholic and holy church regards as aliens. Likewise those who say that there are three Gods, or that Christ is not God, or that before the ages He was neither Christ nor Son of God, or that Father and Son or Holy Ghost are the same, or that the Son is unbegotten, or that the Father begat the Son not by choice or will: the holy and catholic church anathematizes.
1. For neither is it safe to say that the Son is from nothing, (since this is no where spoken of Him in divinely inspired Scripture,) nor again of any other subsistence before existing beside the Father, but from God alone do we define Him genuinely to be generated. For the divine Word teaches that the Unbegotten and Unbegun, the Father of Christ, is One.
2. Nor may we, adopting the hazardous position, ‘There was once when He was not,’ from unscriptural sources, imagine any interval of time before Him, but only the God who has generated Him apart from time; for through Him both times and ages came to be. Yet we must not consider the Son to be co-unbegun and co-unbegotten with the Father; for no one can be properly called Father or Son of one who is co-unbegun and co-unbegotten with Him. But we acknowledge that the Father who alone is unbegun and unbegotten, has generated inconceivably and incomprehensibly to all; and that the Son has been generated before ages, and in no wise to be unbegotten Himself like the Father, but to have the Father who generated Him as His beginning; for ‘the head of Christ is God’ (1 Corinthians 11:3).
3. Nor again, in confessing three realities and three persons, of the Father and the Son and the Holy Ghost according to the Scriptures, do we therefore make Gods three; since we acknowledge the self-complete and unbegotten and unbegun and invisible God to be one only, the God and Father (John 20:17) of the Only-begotten, who alone has being from Himself, and alone vouchsafes this to all others bountifully.
4. Nor again, in saying that the Father of our Lord Jesus Christ is one only God, the only unbegotten, do we therefore deny that Christ also is God before ages; as the disciples of Paul of Samosata, who say that after the incarnation He was by advance made God, from being made by nature a mere man. For we acknowledge, that though He be subordinate to His Father and God, yet, being before ages begotten of God, He is God perfect according to nature and true, and not first man and then God, but first God and then becoming man for us, and never having been deprived of being.
5. We abhor besides, and anathematize those who make a pretence of saying that He is but the mere word of God and unexisting, having His being in another – now as if pronounced, as some speak, now as mental – holding that He was not Christ or Son of God or mediator or image of God before ages; but that He first became Christ and Son of God, when He took our flesh from the virgin, not quite four hundred years ago. For they will have it that then Christ began His kingdom, and that it will have an end after the consummation of all and the judgment. Such are the disciples of Marcellus and Scotinus of Galatian Ancyra, who, equally with Jews, rejected Christ’s existence before ages, and His Godhead, and unending kingdom, upon pretence of supporting the divine monarchy. We, on the contrary, regard Him not as simply God’s pronounced word or mental, but as Living God and Word, existing in Himself, and Son of God and Christ; being and abiding with His Father before ages, and that not in foreknowledge only, and ministering to Him for the whole framing whether of things visible or invisible. For it is He to whom the Father said, ‘Let us make man in our image, after our likeness’ (Genesis 1:26), who also was seen in His own person by the patriarchs, gave the law, was spoken by the prophets, and at last became man and manifested His own Father to all men, and reigns to never-ending ages. For Christ has taken no recent dignity, but we have believed Him to be perfect from the first and like in all things to the Father.
6. And those who say that the Father and Son and Holy Ghost are the same, and irreligiously take the three names of one and the same reality and person, we justly proscribe from the Church, because they suppose the illimitable and impassible Father to be also limitable and passable through His becoming man. For such are they whom Romans call Patripassians, and we Sabellians. For we acknowledge that the Father who sent, remained in the peculiar state of His unchangeable Godhead, and that Christ who was sent fulfilled the economy of the Incarnation.
7. And at the same time those who irreverently say that the Son has been generated not by choice or will, thus encompassing God with a necessity which excludes choice and purpose, so that He begat the Son unwillingly, we account as most irreligious and alien to the Church; in that they have dared to define such things concerning God, beside the common notions concerning Him, so, beside the intention of divinely inspired Scripture. For we, knowing that God is absolute and sovereign over Himself, have a religious judgment that He generated the Son voluntarily and freely. Yet, as we have a reverent belief in the Son’s words concerning Himself (Proverbs 8:22), ‘The Lord created me a beginning of His ways for His works,’ we do not understand Him to have been originated like the creatures or works which through Him came to be. For it is irreligious and alien to the ecclesiastical faith, to compare the Creator with handiworks created by Him, and to think that He has the same manner of origination with the rest. For divine Scripture teaches us assuredly and truly that the Only-begotten Son was generated sole and solely. Yet, in saying that the Son is in Himself, and both lives and exists like the Father, we do not on that account separate Him from the Father, imagining place and interval between their union in the way of bodies. For we believe that they are united with each other without mediation or distance, and that they exist inseparably. All the Father encompassing the Son, and all the Son hanging and adhering to the Father, and alone resting on the Father’s breast continually. Believing then in the all-perfect triad, the most holy, that is, in the Father, and the Son, and the Holy Ghost, and calling the Father God, and the Son God, yet we confess in them, not two Gods, but one dignity of Godhead, and one exact harmony of dominion, the Father alone being head over the whole universe wholly, and over the Son Himself, and the Son subordinated to the Father; but, excepting Him, ruling over all things after Him which through Himself have come to be, and granting the grace of the Holy Ghost unsparingly to the saints at the Father’s will. For that such is the account of the Divine Monarchy towards Christ, the sacred oracles have delivered to us.
Thus much, in addition to the faith before published in epitome, we have been compelled to draw forth at length, not in any officious display, but to clear away all unjust suspicion concerning our opinions among those who are ignorant of our affairs; and that all in the West may know, both the audacity of the slanders of the heterodox, and as to the Orientals, their ecclesiastical mind in the Lord, to which the divinely inspired Scriptures bear witness without violence, where men are not perverse.”