Why Nicea matters: the church before the creed

Ligon Duncan gives a historical introduction to the Nicene Creed. His plenary session looks at the church before the creed and the setting in which the Council of Nicea was convened in 325.

Ligon Duncan, “Why Nicea matters: the church before the creed,” plenary session, Nicea Conference 2025, Istanbul.

Introduction

It’s a privilege to be with you today and to talk about the history around the council of Nicea and it’s appropriate that we would be here in Istanbul discussing Nicea for a variety of reasons. This is a very important city in history. It’s been called by many names. It was once known as Byzantium. Constantine himself called it New Rome. It was eventually named after Constantine and then after the Ottoman Empire was established, it became known as Istanbul. When we call it Istanbul today, we’re actually approximating the name that the Greek-speaking inhabitants of this city called it back when it was Constantinople in the early days of the serving as the seat of the Eastern Roman Empire. The Greeks spoke of going eis tēn polin into the city. They simply referred to this place as the city eis tēn polin.

And you can hear eis tēn polin Istanbul. You’re calling this city what the Greeks called it 1500 years ago when you say Istanbul. So it’s appropriate that we would be here in this great city. It’s also appropriate this is the city where Arius would die. This is the city where Julian the Apostate would be born. And you’re going to hear in this lecture that the pagan Roman emperor Julian the apostate ends up being in the providence of God one of the instruments of the triumph of Nicene orthodoxy. He was born in this city and of course the council of Constantinople will be held in this city in 381 and it will really seal the creedal effect of the council of Nicea. So many of us got to go to Iznik and see the ancient Nicea yesterday. But it’s appropriate that we would be both in Nicea and in Istanbul to consider this great council and the creed that they produced. The Arian controversy, one historian has said, was the greatest theological controversy in the history of Christianity. And I want to think with you for just a few moments about the drama of Nicea and how the church fought for faith in Christ. Let me outline for you what I’m going to try and do today. I want to give you a little bit of an introduction to the council and I’d like to walk you through four stages in the history of Nicea. First from the year 303 to 313 AD 303 to 313 we will look at the persecution that began under the emperor Diocletian up until the edict of Milan in 313 that gave Christians relief from persecution and opposition in the empire. So we’ll go from the Diocletian persecution of 303 to the edict of Milan. That’s the first thing we’ll look at. Then secondly, we will look at the beginnings of the Arian controversy from 318 to 325.

Then we’ll spend some time looking at the Council of Nicea itself. That’s the third section we’ll do. And then finally, we’ll look at the aftermath of the Council of Nicea from 325 to 381 all the way up to the Council of Constantinople and then I’ll offer a few concluding remarks on why Nicea still matters. Now, I will also throw in some points of application along the way. And no doubt when the panel discusses facing heresy in the church they will be able to clean up many of the issues that I am not able to address fully. Let me say be patient with yourself as I overview this history.

There are a lot of strange and unfamiliar names. There are a lot of difficult concepts and other speakers at this conference will be working out in greater detail some of the things that I introduce to you today. So let’s begin by thinking about what was going on in the life of the church before the council of Nicea in 325.

The church before Nicea

In the middle of the 3rd century, that’s about 250 A. 250, the church had experienced empirewide persecutions. The emperor Decius and then Valerian after him had persecuted Christians empirewide and it brought about a crisis in the church. Number one, church leaders were concerned that Christianity was growing so rapidly in the third century that nominalism was a concern for them. That is people professing faith in Christ who were Christian in name only.

nominalism. They weren’t truly disciples of Christ, but they had associated themselves to the church. This was a concern of Christian leaders in the third century. And the persecutions revealed that because what happened was many of the Christians who are persecuted lapsed. They denied the faith. And then there was a pastoral crisis in the church. What do you do when somebody denies the faith? And then after the persecution is over, they come back to the church and they say, “We’re Christians.

What do you do with them?” And there were divisions about what to do with them in the church. And some people said they cannot be restored. If somebody’s denied the faith, if somebody’s denied Christ in the church, they cannot be restored. And others said yes, they can be restored. They’re going to have to go through a process of repentance and they’re going to have to demonstrate the fruit of repentance. So, there was division in the Christian church about what to do about those empirewide persecutions. Well, in 303, the last of the great empirewide persecutions of the Christian church was inaugurated under Diocletian the emperor. And WHC friend in his exposition of the history of the early church to 451 describes the Diocletian persecution this way. On 23 February 303 there was posted an edict in Nicomedia not far from here ordering all copies of the Scriptures to be surrendered and burned. All churches to be dismantled and no meetings for Christian worship to be held.

The next day, a supplementary edict deprived Christians of all honors and dignities, making them all liable to torture and debarring them from being plaintiffs in any legal action. The great church of Nicomedia, which stood in full view of the imperial palace, was completely destroyed. A Christian who tore down a copy of the edicts was caught and roasted alive.

Thus began the great Diocletian persecution. And out of that persecution, the Christian church when it ended was having to rebuild and deal with the scars of imprisonment, martyrdom, and lapsed confessing Christians. What do you do when a person who’s confessed Christ has lapsed, has denied Christ, and now wants to be restored? And in the wake of that persecution relief came in the person of emperor Constantine.

And that’s what I want to point to from the time of 313. You may remember that emperor Constantine won a great battle in 312 that made him the ruler, the sole ruler of the whole Roman Empire. And in 313 he granted religious liberty to Christians. This is the first time that this had been fully done in the days of the Roman Empire. And he himself professed faith and came under the tutelage of very significant Christian leaders in the church. And so as he united the empire, he discovered that there was division in the church over doctrinal matters. And he wanted there to be peace in both the empire and the church.

Arius and Alexander

Now what was he concerned about? Well, th this was the controversy that had been brought about by the teaching of a man named Arius. Arius was a Libyan who was teaching in Alexandria in Egypt. He’s described by one man as tall, ascetic, eloquent, and popular, especially among women. The latter was probably not a compliment.

He wanted to safeguard the uniqueness of God and so he taught a kind of monarchianism that is that there is only one God and therefore Christ cannot be fully identified with that one God. He wanted to safeguard the uniqueness of God. And therefore he taught that Christ was the highest of creatures created before all ages but not eternal not truly God. He further said that if the Father begat the Son then the Son was begotten and therefore had a beginning of existence. And hence it was clear that there was a time that he was not. And that little phrase in Greek enh there was a time when he was not became a rallying cry and motto of the Arian cause. God is God. Christ is the firstborn of creation. And this teaching brought about great controversy in Egypt because Bishop Alexander of Alexandria was a staunch defender of the doctrine of the Trinity and the doctrine of the deity of Christ. And he and his deacon Athanasius insisted if the Son is not truly God, he cannot truly save. It wasn’t a matter of semantics. It was a matter of salvation. Athanasius would ask, “If Christ were a creature, how could he make us sons of God?”

Calling the council

Now, this controversy was raging in the church beginning from about the time of 318. And so, in 325, Constantine wanted to have an ecclesiastical council that would address this particular problem. And I want to read, we actually have the summons that Constantine announced calling the various leaders of the church to this council. And I want you to hear it. I think it’ll be good for you to hear what Constantine himself said. Here’s his summons to the council of Nicea. That there is nothing more honorable in my sight than the fear of God is, I believe, manifest to every man. That’s an fascinating thing for a Roman emperor to say now because it was agreed formerly that the synod of bishops should meet at Ancyra in Galatia. So the modern capital of Turkey is where they had originally planned to have the council meet in Ancyra which is in Galatia. So you remember where Galatia is from your Bibles.

He says, “It seems to us on many accounts that it would be well for that synod to assemble at Nicea, a city of Bithynia.” Now, again, we Bithynia is a word you know from your Bibles. That’s the area we’re in close by. And he says let’s meet in Nicea both because the bishops from Italy and the rest of the countries of Europe are coming and it’s easier for them to get there than it is to get all the way to Ancyra.

And he says because of the excellent temperature of air it would be very comfortable to meet in Nicea in order that I may be present as a spectator and participator in those things which will be done. So Constantine wants to be there himself and to watch and to participate in this church council. And so that’s exactly what happened. In the summer of 325, somewhere between 200 and 300 bishops gathered in the little town, the modern town of Iznik in the ancient town of Nicea, many of them scarred from persecution. And Constantine himself opened the proceedings in imperial splendor, urging unity rather than division. And by the way, Eusebius of Caesarea, the great church historian who’s the author of the ecclesiastical history that many of you have read, one of the early histories of Christianity, describes what Constantine looked like when he arrived at the council of Nicea.

Again, it’s worth you hearing this.

First well when the whole assembly was seated with proper dignity, silence fell on all before the emperor arrived. First three members of his family entered in order of rank and then others came in heralding his own approach. These were not the soldiers or guards who usually accompanied him but friends in the faith. Imagine that, a Roman emperor bringing Christian friends with him in the solemn procession into the assembly. Then everyone stood up as a sign was given that the emperor was about to enter. And at last he himself made his way through the midst of the assembly, looking like some heavenly angel of God, covered in a garment which glittered as if it were radiant with light, reflecting the glow of his purple robe, adorned with the brilliant splendor of gold and precious stones.

And when he reached the upper end of the seats, he remained standing at first. And when a servant had brought a low chair of wrought gold for him, he did not sit down until the bishops signaled him to do so. And then the whole assembly sat down. Now among the two or 300 bishops that gathered at that conference, we can indicate three different groups or parties. The first were the Arians, those who followed the teachings of Arius and then of his teacher Lucian of Antioch. In fact, it’s been said that Lucian was the first Arian and that Arius got many of his teachings from Lucian of Antioch who was a very prominent man who had been martyred in a regional persecution many years before. So the Arian party, they made up only about 20 of the members at the council were part of the Arian party. And that’s a r i a n, not a r y a n. Arian as in named after Arius the teacher.

The parties at the council

The largest group at the council we may call the Origenists. Now, Origen o r i g n was probably the most prominent Christian theologian between Paul and Augustine. He’s often called the first systematic theologian. He was a man of enormous influence and everybody especially in the eastern church was influenced by his ideas and Origen had a view of the relationship between the Father and the Son that emphasized that the Father was of first rank and the Son was of second rank. So he had degrees of divinity in his description of the relationship between the Father and the Son. Now the Origenists were the majority party at the council of Nicea. Far more bishops were influenced by Origen than anyone else.

And they came to the council wanting compromise. They didn’t agree with the Arians, but they wanted compromise on this issue. And perhaps Constantine himself wanted con compromise on the issue. The third group at the council were, we could call them the Nicenes or we could call them the Athanasians, the ones who agreed with Bishop Alexander and with Athanasius, insisting on the full deity of the Son and insisting that the Son was God in the same way that the Father was God, that he shared the same essence as the Father. And these were people like Athanasius and Marcellus of Ancyra.

Well, these parties came together and a great discussion began. It pro this council probably began in either May or June of 325. So, 1700 years and a few months ago, the com the council began and it ends in July because Constantine wants them to celebrate the anniversary of his crowning as the emperor. And so great debates are held between these various groups and ultimately the small group of Athanasians we might call them the small group of Athanasians win the day and their views are upheld. Now how did that happen? Well, partly because the man who was the moderator of the council was a man named Hosius of Cordova in Spain and he had a great deal of influence on Constantine and he was Nicene. He was an Athanasian. Athanasius greatly admired him and speaks very highly of him. And indeed, Hosius had hosted a regional council of bishops in January of 325, and they came up with a doctrinal statement that looks very much like the creed of Nicea. So he I think Hosius wanted to put that in the emperor’s mind that this was a good way to talk about these issues.

The creed of 325

And so the council produced a creed. And I’m going to read not the creed that you’ve been given which is the Niceno-Constantinopolitan Creed. That’s the Nicene Creed as it was edited and elaborated by the council of Constantinople but the language of the original creed of 325. This is what they said.

We believe in one God, the Father Almighty, creator of all things, visible and invisible, and in one Lord Jesus Christ, the Son of God, begotten of the Father, only begotten. And then listen to this language. That is from the essence of the Father, God from God, light from light, true God from true God, begotten not created of the same essence of the Father.

Now there are in that section four anti-Arian clauses. Number one, God the Son of God, the Lord Jesus Christ is from the ousia, from the essence, from the substance of the Father.

And this language is designed as a counterblast to the fundamental principle of Arianism. Arianism taught that Christ had been created ex nihilo out of nothing. Over against that the Nicene Creed says no he’s created ex ousia of the Father out of the essence of the Father. He’s begotten of the essence of the Father. Second true God of true God. The Arians were content to say that Christ was from God and even that the word of God was God, but they would not say that the word of God was true God.

And this clause has the force of laying down that the Son was truly God in every sense that the Father is God. Then there is the language begotten not created. By the way, many of you sing that line at Christmas time when you sing oh come all ye faithful. Very God begotten not created you sing. You’re singing a line right out of the Nicene Creed. When you do that he is begotten not created.

So notice the distinction that they’re making. The Son was not created. He was begotten. So whatever begotten means it’s not created. And again this is something that they could actually appeal to the language of origin on because Origen had said that the Father eternally begott. So a when you say that the Son is begotten you’re not making a temporal distinction as if the Father existed and then the Son was begotten. No, the Son is eternally begotten. In fact, think about it. How can be the how can the Father be a father without the Son? The Father can’t be the Father without the Son. The Son can’t be the Son without the Father. They eternally coexist. So, begotten not created or made. And then the fourth and final anti-Arian clause is this one. He is of the same essence as the Father. And that phrase contains the full weight of the Nicene reply to Arianism. The word there is he is of the same essence as the Father. He is hama. He is of the same essence of the Father.

Now that word was controversial because it had been used by a famous teacher in the east to teach a particular form of modalism and so the word homoousios was out of favor with many of the Origenist theologians in the east but it was Constantine who suggested the word so it was a little hard to turn down the emperor when the emperor suggested the word but it’s likely that it’s Hosius of Cordova who is the one who is suggested to the emperor that that is the right word to use. And so the relationship between the Son and the Father is described with the term homoousios. They are of the same essence of the same substance. And that that word was the death blow to the Arian cause at that council. The creed was affirmed and at first things seemed to go well. Arius was exiled. His books were ordered to be burned. Even many of the semi-Arians at the council reluctantly signed but what happens in the wake of Nicea is the issues not settled we really go into a period and this is the third third thing that I want to point to you today that era from 325 to 381 we go into a period of time where the interpretation of the creed is debated and the outcome is uncertain. So let me sketch out for you four different stages between 325 and 381 the rest of the life of Constantine. So all the way to 337 from 325 to 337 as long as Constantine is alive the council of Nicea the creed of Nicea is okay nobody’s going to challenge it while the emperor is alive because the emperor agrees with the council when Constantine dies however things change and so from 337 to 346 6 the Arians gain the upper hand.

After Nicea

Then in 346 from 346 to 356 Athanasius is back in influence again. And then from 356 to 360 it seems like the Arians have completely won. So notice we go Nicene Arian in the years from 325 all the way up to 360. So let me talk about those four stages very briefly.

In the first stage from the time of the council of Nicea to the death of Constantine the wording of the Nicene Creed was sacrosanct. The emperor had suggested the wording and to quibble with the wording would be to endanger the your ecclesiastical position, but the interpretation of the creed was not agreed upon and all the parties that were there at the council still existed and everybody was angling to continue to keep their own formulations.

But at the towards the end of that time, right before the emperor died in 335, some enemies of Athanasius in Egypt managed to get him in trouble with the emperor. Now, and this is very interesting, friends. You think ecclesiastical politics are rough today? You listen to what Athanasius enemies accused him of doing to the emperor. They accused him of attempting to levy a tax in Egypt in order to provide his clergy with fine linen vestments.

How do you think that would have gone down? Especially with people that admired ascetics, people that admired denying yourself. You he levied a tax in order to provide his clergy with fine linen vestments. Then they charged him with sending a purse of gold to a powerful official who was in disgrace of bribing a public official. Then they charged him of mistreating a priest, defiling the man’s church, breaking the eucharistic chalice, and throwing down the altar. And in fact, they charged him with murdering a bishop.

And Athanasius was only able to defend himself by producing the bishop alive. In fact they said they accused him of murdering the bishop and then using his hand to do magical rites. And the only way he was able to alleviate himself of these charges was prod was to produce the bishop. But finally they told Constantine, “You know what? He has been trying to stage a blockade of the port in Alexandria to keep you from getting certain things that you want to get.” And that was the last straw. And Athanasius is exiled for the first time. And so the end of that period, right before the end of Constantine’s life, is not good for Athanasius. He’s out of the picture and out of power. Then from 337 to 346, the Arians are they are ascendant because the emperor after Constantine is pro-Arian or semi-Arian and the Arian bishops have influence on him.

Athanasius is brought back in 346 and enjoys about 10 years of influence. Some of his greatest theological influence is exercised from 346 to 356. But then he is again exiled and in 356 to 360 the Roman emperor is again Arian. And the Arians hold several major synods, especially the council of Sirmium and they pass a creed that is almost the exact opposite of the Nicene Creed and they say that Christ is not only of not the same essence of the Father, they don’t even say that he’s of like essence of the Father. They say that he’s not like the Father at all.

And it’s a real it’s a it’s a dark place. It looks like Nicene theology has lost. In fact, Jerome writing on that period says after the creed of Sirmium is passed, the whole world awoke and groaned to find itself Arian. It looked like the Arians had completely won. And then what happened? The Arian emperor died and Julian the apostate came to the throne. And now Julian born in this city had been reared as a Christian. But he was the last Roman emperor to try and take Rome back to paganism. He had apostasized from Christianity and in his short reign he tried to take Rome all the way back to paganism and adopt the old ways. He was very influenced by neoplatonic philosophy. And it’s interesting it said that the only clergyman that he feared was Athanasius.

Now he had a very short reign and he was killed in a battle against the Persians. And when he was killed, the man who came to the throne was a man named Jovian who was a Nicene Christian. And he im in fact he restored Athanasius and had Athanasius process with him. And so Athanasius was able to live to see some of the vindication of his position in public. But actually he died before the council of Constantinople would be held in 381 where the final Nicene creedal victory would be won. After Jovian eventually there was an emperor named Theodosius who came to the throne. Theodosius established Nicene orthodoxy and called for the council of Constantinople to be held in this city in order to affirm the doctrines that had been discussed at Nicea. Now that what does all this matter? You’re going to be studying this for the next two days. What does all this matter? One thing that strikes me about this whole story is God’s providence.

You know, it looked like the Arian cause was going to win. How did God defeat that? He put a pagan emperor on the throne. You never would have guessed that would be the way that God would bring about the triumph of orthodoxy.

The Cappadocians

Of course, that’s not the only way. God raised up several young men that were born in the years right after the council of Nicea, a man named Basil the Great. And Gregory of Nazianzus and these young men Basil and Gregory Nazianzen and Gregory of Nyssa the great Cappadocian fathers they were very influenced they loved the theology of Origen but to their credit they heard the arguments of the Nicenes and they were able to craft language to help the church understand itself. One of the things that had plagued this controversy from the beginning of the 4th century was that Latinspeaking western Christians and Greek-speaking Eastern Christians were talking past one another because they were using different terminology. In general Greek will have more precise theological words available than Latin will and when you’re translating from Latin into Greek it can be very tricky. So for instance the Latin term substantia wi was being used to translate two Greek terms ousia essence and hypostasis individuality or person and what that meant was that the eastern church and the western church had a great miscommunication on those topics. So in Alexandria, you might say that God exists in three hypostasis. And your friend in Rome who speaks Latin would read this and think that you’re saying that God exists in three substances. That is that you’re talking about tritheism.

Or the Latins might say that God exists in one hypostasis and three personae. That’s the language of Tertullian. Now the problem is in Greek personae translates into a word that means an actor’s mask. And it sounds like you’re teaching modalism. That there’s one God and sometimes he appears as father and sometimes he appears as son and sometimes he appears as Holy Spirit. So the Greeks think their Latin friends are teaching modalism. The Latins think the Greeks are tritheists. The Greeks think the Latins are modalists. What happens with the Cappadocian fathers is they come along and they clarify this and they say, “No. When we say ousia, we’re talking about the essence of the one true God. When we say hypostasis, we’re talking about the persons of the Trinity, Father, Son, and Holy Spirit.”

And so the Cappadocians go a long way in clarifying that they go beyond Origen. They revere Origen, but they are more biblical than Origen in the way that they articulate not only the relationship of the Son to the Father, but the doctrine of the Trinity. So another lesson is it’s really important to pay attention to theological terminology.

Sometimes we can use different words to mean the same thing. Sometimes we can use the same words to indicate different things and we have to be pay very attent very close attention to theological terminology. Another important lesson of Nicea is the influence of professors and teachers.

So think about Lucian of Antioch had a tremendous impact on Arius and that became a and Lucian was a martyr. He died for the faith and because of that you know there were people that had respect for his teaching but his teaching was not sound and Arius’s teaching was not sound. So the influence of unsound professors or teachers of theology can be devastating.

Even Origen, Origen’s teaching had a very unhealthy effect until the Cappadocians came along and provided a better rendering of theological terminology. And of course most important is this Athanasius’s understanding of the importance of the person of Christ to the work of Christ. A son who is not fully divine cannot make us sons of God. How can we be made sons of God? By one who is not fully and in every sense the Son of God.

Why it mattered

For Athanasius that was the great question. If Christ is not fully divine, how can he be our savior? And so there was an understanding that your theology proper, your doctrine of God, your Christology, your doctrine of Christ is very important to your soteriology, your doctrine of salvation. And if you have a wrong doctrine of God and you have a wrong doctrine of Christ, you will compromise the gospel. It’s very clear that men like Hosius and Athanasius were involved in this controversy not because they just wanted to bring unity but because they were concerned about the gospel of salvation in Christ. Their great concern was the preservation of the gospel of salvation in Christ. This is so important for us as Protestants especially. We should understand this. Stephen Prothero is an unbelieving student of world religions and he wrote a book called God is not one. And you can hear that that even the name of the book is sort of an attack on the Shema, hear O Israel, the Lord your God, the Lord is one. So God is not one. But why does he say in his world religion book God is not one? He says that because in liberal Protestant studies of world religions for the last 125 years the basic argument has been all religions are the same and he this is an unbeliever now writing he says that’s wrong that it’s wrong all religions are not the same and believing that will get you killed. So it’s a very interesting book. One of the things that he says in that book is Christians have the only religion that’s really interested in doctrine.

And he says, “Now, why is that?” And he says, “It’s because of this. In Christianity, it’s not what you do that saves you. It’s what God has done for you in Christ that saves you.” And that means that explaining that doctrine is absolutely essential to salvation. The gospel is irreducibly doctrinal.

And Athanasius and the Nicenes understood that. And that is why they took the stand that they did at the council of Nicea. And that’s why it’s so good that we’ve gathered again 1700 years to remember again the importance of true biblical doctrine to the work of the gospel. When we share the gospel, we share an irreducibly doctrinal call to salvation. God has saved us in the person of his only begotten Son who is fully divine and fully human and died for us in our place bearing our sins so that all who rest and trust on him alone for salvation as he is offered in the gospel are forgiven and pardoned and accepted justified through his blood. Praise God for the work of the council of Nicea.