Arguments Supporting the Doctrine of the Trinity

One of the principal arguments supporting the doctrine of the Trinity is the simple, repeated reference to the Three who make up the Godhead. The Father, the Son and the Holy Spirit are referred to in concert in many places in the bible.

At the outset, I am aware of the unitarian arguments against each of the points I am about to make. As in my previous article, I will refrain from making the counter case. I will simply lay out the arguments supporting the doctrine of the Trinity in this article.

Scriptural Arguments Supporting the Doctrine of the Trinity

Well, perhaps these are not arguments supporting the doctrine of the Trinity, as such. Certainly the following scriptures establish the understanding of the Trinity in the New Testament.

In Matthew 28:19, Jesus commands his disciples to baptise “in the name of the Father and of the Son and of the Holy Spirit”.

Therefore go and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit

Matt 28:19 (NET)

This command clearly identifies the integrity of each separate and distinct part of the Godhead. Three separate and distinct individual entities who have a keen interest in the individual being baptised.

Paul in 2 Corinthians 13 is pretty clear about the three fold relationship we hold with Jesus Christ, God and the Holy Spirit. He actually describes the relationship in specific terms of grace, love and fellowship.

The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all.

2 Cor 13:13 (NET)

In 1 Peter 1, this threefold relationship and how it acts in our calling is specified. By God the Father’s foreknowledge, in obedience in the Spirit and through Jesus’ blood…

according to the foreknowledge of God the Father by being set apart by the Spirit for obedience and for sprinkling with Jesus Christ’s blood. May grace and peace be yours in full measure!

1 Pet 1:2 (NET)

John 1:1 presents Jesus, referred to as the Word in this text and identifiable as such by context and many other parts of Scripture. He is identified as “fully God”.

In the beginning was the Word, and the Word was with God, and the Word was fully God.

John 1:1 (NET)

In Colossians 1, Jesus is identified as the image of the invisible God, in whom all God’s fullness dwells.

He is the image of the invisible God, the firstborn over all creation, for all things in heaven and on earth were created in him—all things, whether visible or invisible, whether thrones or dominions, whether principalities or powers—all things were created through him and for him. He himself is before all things and all things are held together in him. He is the head of the body, the church, as well as the beginning, the firstborn from the dead, so that he himself may become first in all things. For God was pleased to have all his fullness dwell in the Son and through him to reconcile all things to himself by making peace through the blood of his cross—through him, whether things on earth or things in heaven.

Col 1:15-20 (NET)

Again, in each of the scriptures, there is a contrary view held by unitarians and I understand this, nevertheless, it is difficult to deny the deity of Jesus clearly stated in these basic scriptural proofs.

Appealing to History

Unitarians attempt to argue that their’s is an apostolic faith with the weight of history behind it. In fact, the weight of history would align more with Trinitarians where there are extensive historically attested documents supporting an early belief in the doctrine of the Trinity. In the arguments that support the doctrine of the Trinity, this doctrine existed in the church fathers Augustine and Athanasius to Basil. It certainly came to a head in the 4th Century with the rise of the Arian controversy. That is why we get substantial writing around this time especially from the three mentioned in this paragraph.

Divine groups of three appear in many ancient religions whether of males, females or Father-Mother-Son groups. Some had three faces with one body and other purmutations. Plato’s followers, Numenius and Philo dabbled in doctrinal models of the trinity. Of course, this proves nothing. Stories of universal floods are extant across the globe too. I doubt that Unitarians would assert that this is evidence of biblical copying.

Unitarians argue that the doctrine of the Trinity came to Christianity from Plato by way of Justin Matyr (d 165AD). It may well be that Justin attempted to articulate the doctrine using the Platonic model. This does not prove that the doctrine itself originates from Plato’s teachings as such.

Diverse Theology in the Early Church

There is no doubt that prototypical Christianity prior to 325AD was pretty diverse theologically with an array of doctrines. At one end of the spectrum (and not exactly Christian in nature) was gnosticism. This was what the Apostle John was dealing with in his letters at the end of the new Testament. At the other end of the spectrum were beliefs around the nature of God. Arius advocated for a form of unitarianism and others advocating for the Trinitarian viewpoint.

The Christian theology “subordinationist” was another derivation held by Origen (185-255AD). It held that God the Father was superior, The Son is subordinate and the Holy Spirit subordinate again. This too is a form of unitarianism but does admit the personhood of the Spirit.

Tertullian (160-225) seems to have been an early documenter of the doctrine of the Trinity. This was admittedly in a somewhat different perspective to the more final form of the doctrine later extant.

Critical Mass

Ultimately, the Arian controversy which flew in the face of what had become standard doctrine forced the bishops of the period to join in a clear statement of doctrine. A sharp divide was drawn between the various subordinate theorists such as Arius and the main body of Christendom. This culminated in a council of bishops convened by Constantine the Great. Thus the Doctrine of the Trinity was asserted at least in some form. Gregory of Nyssa, Basil of Caesarea and Gregory Nazianzus more fully articulated the doctrine over the next century.

Contrast the History of Modern Unitarianism

You can’t trace Modern Unitarianism back to Arius and Tertullian. They at least acknowledged the personhood of the Holy Spirit as well as the deity of Jesus. You can trace Modern Unitarianism back to 16th Century reformation era in Poland or John Biddle in the UK about a century later. Potentially you can trace Anti Trinitarian beliefs back to the Council of Nicaea in 325AD. As we have seen above, these would not be necessarily a denial of all aspects of the Trinity. Indeed, any doctrine that denied the Trinity would appear to have disappeared for at least 700 years.

The tradition that I come from appears to me to closely link to the Italian Sozzini uncle and nephew. It rejects the pre-existance of Jesus. It asserts that he did not exist until he was conceived as a human (in stark contrast to John 1:1). The Sozzini’s also held a range of other doctrines that conflicted with mainstream Christianity and that are not held by the Christadelphians.


To claim to have a clear, unequivocal understanding of the nature of God is to fly in the face of what Scripture has revealed about Him over the whole of Scripture. There are many paradoxes about the nature of God that are hard to explain in human terms. Take for example the fact that God has no beginning and no end, that He is everywhere present, that He knows the beginning from the end (yet He can be persuaded to change His mind) and many other mysteries.

The paradoxical nature of three fully divine persons in one God is not the basis of an argument against the Trinity. I believe that the bible reveals this about God in His three persons, just as it reveals a God who has no end and many other strange things about God that I can’t fully comprehend. Whilst this is not one of the arguments supporting the doctrine of the Trinity, neither is it an argument against.


I get that the foregoing may be a bit frustrating for those who would like to refute the arguments supporting the doctrine of the Trinity, but I am laying a foundation here for the following articles where I will tackle the main arguments for and against.

For now, let me just reaffirm this:

Jesus outright claimed unity with the Father in John 10:30 and claimed pre-existence in John 8:58. Thomas recognised Jesus as God (and Jesus did not dispute this) in John 20:28. Paul in Philippians 2 states that Jesus was God (“in the form” denotes a correspondence with reality) and in Colossians 1, details Christ’s position as God the Son.

Paul in Acts 5, equates lying to the Holy Spirit with lying to God. The Spirit judges as God in John 16:8-11. The Spirit is the conduit of God’s Love in Romans 5. There are many other quotes assigning Gods attributes to the Holy Spirit which I will leave for a later article.

Ultimately, the arguments supporting the doctrine of the Trinity are in fact evidence from Scripture and in later articles I will detail many of them. They are not arguments from logic or even really history, but rather the clear statements of Christ regarding his own nature and the nature of Holy Spirit.

In the next few articles, I will delve into the specific contentions of unitarians against the Trinity and attempt to counter them.

You may also like...