This is one in a series of articles on the Christian doctrine of the Trinity. To see MRM’s website page on the Trinity to see other resources, please click here.

By Eric Johnson

Christians believe that the Trinity is originally taught in the Bible. However, the word “Trinity” did not come until later in Christian church history. Below is a sketch of the doctrine, with much of the information coming from E. Cal Beisner’s God in Three Persons (Wheaton: Tyndale, 1984).

First Century (the Apostles)

The teaching of the Trinity is limited to the New Testament, the Didache, the writings of Clement of Rome around the time of the destruction of the temple (AD 70), Barnabas (around AD 75), and Hermas (AD 75-85). Matthew 28:19-20 gives a good picture of the Trinity:

Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age.

Notice how it says “name” (singular) as described in three persons: the Father, Son, and Spirit. The Didache (AD 35-60), an early Christian source, explains:

But concerning baptism, thus shall ye baptize. Having first recited all these things, baptize in the name of the Father and of the Son and of the Holy Spirit in living (running) water. . . . But if thou hast neither, then pour water on the head thrice in the name of the Father and of the Son and of the Holy Spirit.

Second Century (Apostolic Fathers)

More is written about the deity of Jesus than the Holy Spirit. When it comes to baptism, Justin Martyr explained:

For, in the name of God, the Father and Lord of the universe, and of our Saviour Jesus Christ, and of the Holy Spirit, they shall receive the washing of water.

Irenaeus was a disciple of Polycarp, who had been a disciples of the apostle John. In his Against Heresies X.1, he wrote:

The Church, though dispersed throughout the whole world, even to the ends of the earth, has received from the apostles and their disciples this faith: [She believes] in one God, the Father Almighty, Maker of heaven and earth, and the sea, and all things that are in them, and in one Christ Jesus, the Son of God, who became incarnate for our salvation; and in the Holy Spirit, who proclaimed through the prophets the dispensations of God, and the advents, and the birth from a virgin, and the passion and the resurrection from the dead…

He also wrote:

This, then, is the order of the rule of our faith. . . 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 this: 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 Father’s dispensation, through Whom (i.e. the Word) all things were made; Who also, at the end of the age, 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 perfect reconciliation 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 into the way of righteousness; Who at the end of the age was poured out in a new way upon mankind in all the earth, renewing man to God.

These things were stated in such a short time after the death of the apostles in a rather concise and formalized pattern. As Beisner writes:

The closeness of the relation of these writers to the apostolic age cannot be underestimated, for the powerful shaping force of those first followers of Jesus would surely continue even by purely oral tradition, let alone the powerful control their writings had, for at least three generations of Christians. It is wrong to say that the Trinity is far separated from apostolic teaching, even if we neglect the fact that it is taught in the New Testament, for the apostles’ hold over the first several generations of Christians connects them strongly with what those later Christians taught (p. 51).

The first use of the Trinity comes from Theophilus:

In like manner also the three days which were before the luminaries, are types of the Trinity, of God, and His Word, and His wisdom.

Referring to the use of “Trinity” here, Beisner writes on page 54 that it

bears all the marks of a word which had long become a commonplace in the Christian community. One does not speak obliquely of “types” of something with which one’s readers are not at least fairly well acquainted. So while we may date this use of the word sometime from, broadly speaking, AD 150-175, we are forced to assume that the word was in regular use before that. It would not be unreasonable to guess that it has roots as early as three to five decades before, perhaps even earlier. This brings us back again to the early part of the second century. And even this, the earliest known use of the word, remains within two generations of the last of the apostles.

Third Century (Apologists and Polemicists)

Because there was so much persecution and heresy, Christian Church Fathers had to be more precise with their description and defend their teaching. For example, Tertullian argued against the heresy called Monarchianism (stressed the unity of the Godhead while denying the plurality of the Persons). Beisner writes:

Tertullian’s formulations of the doctrine of the Trinity are quite sophisticated, and clearly foreshadow the formulation decided upon at the Council of Nicaea. “The Latin word for Trinity (trinitas), ocurs for the first time in Tertullian’s (Against Praxeas), and his phrases tres personae (three Persons) and una substania (one substance) anticipated the orthodox trinitarian formula.”

Tertullian wrote:

Thus the connection with the Father in the Son and of the Son in the Paraclete, produces three coherent Persons, who are yet distinct One from Another. These Three are one essence, not one Person, as it is said, “I and my Father are One,” in respect of unity of substance, not singularity of number.

This was written in response to the Monarchian claim that John 10:30 (“I and the Father are one”) proves that the two were the same person. However, as Tertullian pointed out, the Greek word for “one” is neuter, not masculine, which means their unity was one of substance, not person.

Another defender of the Trinity was Hippolytus, a disciple of Irenaeus and who, like Tertullian, also attempted to refute Monarchianism. He battled against the idea that the Father was the same person as the Son and the Holy Spirit.

Fourth Century

The teaching of Arius declared that Jesus was a created being and was not “very God of very God.” This heresy was met head-on at the Council of Nicaea (AD 325) convened in Turkey by the emperor Constantine. Arius taught that only God the Father is eternal and that Jesus had a beginning since he was a created being. He claimed that Jesus was called God only as an honorific title. Athanasius disagreed, saying that Christ is co-eternal with the Father and that He had no beginning. He also claimed that the Son and the Father are of the same essence.

At the council the bishops formally condemned Arianism and determined that Jesus was, indeed, God in the flesh. This provided the chance for more description to be added to the character of Jesus. Beisner explains:

The Nicene Creed came from this council, and it stated:

We believe in one God, the Father, the Almighty, maker of heaven and earth, of all that is, seen and unseen.

We believe in one Lord, Jesus Christ, the only Son of God, eternally begotten of the Father, God from God, Light from Light, true God from true God, begotten, not made, of one Being with the Father. Through him all things were made. For us and for our salvation he came down from heaven: by the power of the Holy Spirit he became incarnate from the Virgin Mary, and was made man. For our sake he was crucified under Pontius Pilate; he suffered death and was buried. On the third day he rose again in accordance with the Scriptures; he ascended into heaven and is seated at the right hand of the Father. He will come again in glory to judge the living and the dead, and his kingdom will have no end.

We believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father. With the Father and the Son he is worshiped and glorified. He has spoken through the Prophets. We believe in one holy catholic and apostolic Church. We acknowledge one baptism for the forgiveness of sins.  We look for the resurrection of the dead, and the life of the world to come.  Amen. (Note:  The word “catholic” with a lower case ‘c’ does not mean the Roman Catholic Church but the universal Christian Church as a whole.)

Although the Council of Nicaea ended with a rousing paper victory for the orthodox, the victory was not to be complete until fifty-six years later, at the Council of Constantinople. Shortly after the Council of Nicaea, the Arians made a powerful comeback, taking the reins of power in the Church, at least in the East (p. 124).

Arianism was again rebuffed at the Council of Constantinople in AD 381, and the heresy of Macedonianism (the denial of the Holy Spirit as God) was denied while the Holy Spirit’s deity was affirmed. Out of this council came the Nicene-Constantinopolitan Creed:

We 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 Son of God, Begotten, not made; of one essence with the Father, by whom all things were made:
Who for us men and for our salvation came down from heaven, and was incarnate of the Holy Spirit and the Virgin Mary, and was made man;
And was crucified also for us under Pontius Pilate, and suffered and was buried;
And the third day He rose again, according to the Scriptures;
And ascended into heaven, and sits at the right hand of the Father;
And He shall come again with glory to judge the living and the dead, Whose kingdom shall have no end.
And we believe in the Holy Spirit, the Lord, and Giver of Life, Who proceeds from the Father, Who with the Father and the Son together is worshipped and glorified, Who spoke by the Prophets;
And we believe in one, holy, catholic, and apostolic Church.
We acknowledge one Baptism for the remission of sins.
We look for the Resurrection of the dead,
And the Life of the age to come. Amen.

Beisner concludes:

The Nicene-Constantinopolitan Creed comes at the end of three-and-a-half centuries of battle against gnosticism neo-plantonism, subordinationism, polytheism, Monarchianism, and finally Arianism, each with many forms. It expresses the faith taught in the New Testament as contrasted with all the variations offered by the unorthodox in the past who failed to represent that faith accurately. The Nicene Creed stands as the great hallmark of truly Christian trinitarianism against all pseudo-Christian trinities (p. 142).