I do not accept the common historical belief that the doctrine of the Trinity was developed over time and then finalized at Nicea. I hope I have already established that there is a consistency from the time of the apostles all the way through the Council of Nicea.
It certainly was not finalized at Nicea. We have seen that the Nicene Creed was adapted into the Athanasian Creed which then became our modern doctrine of the Trinity. The Nicene definition of the Trinity, for the most part, is long forgotten.
However, if I am going to take a stand—and teach it on this web site—that is not accepted and popular among historians, I want to prove it thoroughly. Therefore, I want to give you plenty of evidence that the Nicene doctrine of the Trinity did not develop but is taught throughout the earliest Christian writings after the apostles.
Let's begin with Eusebius, the historian.
Eusebius' Ecclesiastical History was written in A.D. 323 and is still published in several formats today. Many people who have not read anything else from the primitive church have read his history.
Eusebius wrote a letter after the Council of Nicea justifying its conclusions. He wrote for good reason. It was the "rule of faith" of his church, Caesarea, that was used as the basis for the Nicene Creed, and he was explaining the adaptations that the council had made.
Because that letter is written so apologetically, Eusebius' adherence to an orthodox doctrine of the Trinity is questioned.
Worse, when people read the Nicene Creed through the eyes of the modern doctrine of the Trinity, Eusebius' orthodoxy is even further questioned. As we have seen, there are places where the Nicene doctrine of the Trinity and our modern teaching conflict.
But Eusebius is possibly the best witness of the consistency of the pre-Nicene doctrine of the Trinity. His Ecclesiastical History is replete with quotes from the writers before him. In fact, much that has been lost and is unavailable today is preserved in his writings.
If the Church in its earlier days had believed anything different from Nicea, or if the doctrine of the Trinity had developed over time, no one would know better than Eusebius. However, instead of testifying to change, Eusebius defended the Nicene Creed with these words:
Here he agrees with the use of homoousios because it was used by earlier writers. We have seen on this page how Tertullian regularly refers to the substance of God in his writings. Eusebius was aware of this.
Let's become aware of that ourselves. Let's simply begin at the beginning, in the earliest of the Christian writings after the New Testament.
One of the very earliest Christian writings is the anonymous letter to Diognetus. It may have been written as early as A.D. 80, though its date has been difficult to determine. Even at this early date, however, we can see the Nicene doctrine of the Trinity.
This anonymous author was not trying to explain the doctrine of the Trinity, but he leaves us several clues that he held to the Nicene faith.
Here's another one:
There are other Christian writers between the Letter to Diognetus and Justin Martyr, but none of them say anything clearly about the doctrine of the Trinity, except perhaps this quote from Clement of Rome:
Justin, on the other hand, says a lot about the doctrine of the Trinity because he's having to explain to a Jew why Christians call more than one Divine Person God.
He actually makes his first mention of the Divine Logos in his letter to the emperor, referred to as First Apology. He argues that the Logos imparted wisdom to Socrates in order to allow him to correct the demon worship of the Greeks.
He is very direct in Dialogue with Trypho, a Jew
Justin even provides illustrations of how such a begetting might have happened!
He then adds the typical reference to Proverbs 8:22:
Justin's belief in Jesus as the Logos of God generated in eternity past is so clear that references are made to Justin's "Logos doctrine." However, his Logos doctrine is the same one that all other well-instructed early Christians believed.
Irenaeus is another important witness to the apostolic age, having sat under the teaching of Polycarp who had been appointed bishop of Smyrna by the apostle John. Irenaeus was a missionary to barbarians in Gaul (modern France) who supervised several churches in and around Lyons.
In his famous treatise Against Heresies, he writes:
Even more clearly, he says:
Clement of Alexandria, not to be mistaken with Clement of Rome from a century earlier, wrote in the late 2nd century. He was a prolific writer who trained new Christians in Alexandria, Egypt.
In a discussion on 1 John (Fragments of Clement of Alexandria: Comments on the First Epistle of John from The Ante-Nicene Fathers, vol. II), Clement discusses the generation of the Son of God:
When [John] says, "from the beginning," the elder explained to this effect, that the beginning of generation is not separated from the beginning of the Creator. For when he says, "That which is from the beginning," he touches on the generation without beginning of the Son, who is co-existent with the Father. There was, then, a Word importing an unbeginning eternity, as also the Word itself, that is, the Son of God, who being by equality of substance one with the Father, is eternal and uncreated.
Theophilus is several bishops removed from Ignatius, an earlier bishop of Antioch, writing as he did in A.D. 168.
Antioch, remember, was Paul's home church.
Theophilus also bore a very clear understanding of the doctrine of the Trinity as taught by the Nicene Creed.
You can't get a much more precise exposition of the Nicene Creed, and this was 157 years before the Council of Nicea convened to discuss the doctrine of the Trinity.
Athenagoras was an apologist who wrote in A.D. 177. His Plea for the Christians is addressed to an unbelieving emperor.
In it, he writes:
This is another extremely clear exposition of the doctrine of the Trinity found in the Nicene Creed, but Athenagoras, a skilled writer, is able to make it even more clear!
Did Athenagoras actually read the Nicene Creed?
He couldn't have, of course, but this does make you wonder whether the Nicene Council read A Plea for the Christians! And of course they did because Eusebius the historian, well familiar with Athenagoras and his letter, was at the Council of Nicea!
There's no real need to address 3rd century quotes. Our job in this section is to establish that the doctrine of the Trinity taught in the Nicene Creed did not develop, but remained the same from the apostles to Nicea. If the 2nd century churches consistently taught the Nicene doctrine of the Trinity, then 3rd century churches—being in between the 2nd century and Nicea—did as well.
We explained the Nicene Creed earlier using Against Praxeas by Tertullian, who wrote at the beginning of the third century, so we have looked at one 3rd century writer.
I believe this is all the evidence needed to establish that the doctrine of the Trinity did not develop during the Pre-Nicene era, but that it remained the same from the apostles to the Council of Nicea.
No wonder Irenaeus was able to write:
You thought I'd never get here, didn't you?
This is very long for a web page, but I believe this is the clearest, most thorough overview of the doctrine of the Trinity in the early church on the internet—or, for that matter, even in a Christian bookstore.