Goths and Eusebius of Nicomedia

 Ostrogoth jewellery at Metropolitan Museum of Art

Sailko wikimedia

Christ reached the Goths at the borders of Roman empire while they were living in paganism that is not very well known to us from historical sources. The pious captives, especially Roman and Anatolian women, brought Him in their hearts and words and example of life to the new husbands and lords. Apparently Goths treated these civilized captives, wives and slaves, with dignity and wanted to learn from them.

At the time of the early conversion of the Goths the Kingdom of Christ was in the midst of very serious process of defining in a binding way the fundamental statements of faith - what is faith in God after what happened in Jesus Christ? Who is this Christ and what is His relation to His Father that He talks so much about?

There were no easy solutions and there is an amazing spectre of theological opinions, all based in the Scriptures in one way or other, emphasizing this or that. Groups of believers were stamped with theological names usually according to their leading theologian and the fight between the groups was not limited to writing pamphlets and learned books stretching the versatile Greek language to the limit.

The first Ecumenical Councils at Nicea 325 and Constantinople 381 were dealing with the most essential theological questions. There Christianity formulated the doctrine of the Holy Trinity. Major concern in these discussions was the rational teaching of Arius and his disciples who insisted that Son is not equal to Father. This seemingly innocent battle that in reality is of the deepest significance to Christian faith reached the highest political levels in the courts of the Roman emperors.

Christianity was now quickly becoming the state religion instead of Greco-Roman paganism forcefully demanded from all citizens. It was now imperative that the new religion would be internally united and thus function as the glue that keeps the enormous Empire internally together. Heretics were now the threat to unity but what was Orthodoxy?

The Credo of Nice-Constantinople had a crucial role in defining orthodox Christianity and the major camps during the 4th century were the Niceans and the Arians who rejected the Creed of Nicea.


Eusebius of Nicomedia
We do not know the birthday of Bishop Eusebius of Nicomedia. He died in Constantinople Anno Domini 341.

This is the man who baptised Constantine the Great resting at his death bead and so brought the emperor to the Kingdom of Christ on May 22, 337.

Eusebius of Nicomedia was also the bishop who ordained Wulfila as the bishop and apostle of the Goths and thus was the key persion in directing these people towards Arian Christianity.

Monk Rufinus of Aquileia (340/345 – 410) has recorded important sources also about Eusebius of Nicomedia. Wikipedia article uses hi through Philip R. Amidon, The Church History of Rufinus of Aquileia: Books 10 and 11. New York: Oxford University Press (1997) when describing the crucial events 325 and the years immediately after the Council. 


After being the Bishop of Berytus (Beirut) and then of Nicomedia Eusebius finally came to Constantinople in 338 staying there near the hubs of political and ecclesiastical power until his death in 341.

Distantly related to the imperial family of Constantine, he owed his progression from a less significant Levantine bishopric to the most important episcopal see to his influence at court, and the great power he wielded in the Church was derived from that source. In fact, during his time in the Imperial court, the Eastern court and the major positions in the Eastern Church were held by Arians or Arian sympathizers.

With the exception of a short period of eclipse, he enjoyed the complete confidence both of Constantine and Constantius II and was the tutor of the later Emperor Julian the Apostate; and it was he who baptized Constantine the Great on May 22, 337. Also during his time in the Imperial court, Arianism became more popular with the Royal family.

It can be logically surmised that Eusebius had a huge hand in the acceptance of Arianism in the Constantinian household. The Arian influence grew so strong during his tenure in the Imperial court that it wasn't until the end of the Constantinian dynasty and the appointment of Theodosius I that Arianism lost its influence in the Empire.

Like Arius, he was a pupil of Lucian of Antioch, and it is probable that he held the same views as Arius from the very beginning; he was also one of Arius' most fervent supporters who encouraged Arius. It was also because of this relationship that he was the first person whom Arius contacted after the latter was excommunicated from Alexandria by Alexander. Apparently, Arius and Eusebius were close enough and Eusebius powerful enough that Arius was able to put his theology down in writing. He afterward modified his ideas somewhat, or perhaps he only yielded to the pressure of circumstances; but he was, if not the teacher, at all events the leader and organizer, of the Arian party.
(wikipedia)

However, despite of his strong leaning towards the teachings of deacon Arius Eusebius signed the Nicene Creed. This act, the signing of such a significant confession against his inner beliefs tells us much about the character of the man.

At the First Council of Nicaea, 325, he signed the Confession, but only after a long and desperate opposition in which he "subscribe with hand only, not heart" according to ancient sources. It was a huge blow to the Arian party since it was surmised that the participants in the First Council of Nicaea were evenly split between non-Arians and Arians. His defense of Arius angered the emperor, and a few months after the council he was sent into exile due to his continual contacts with Arius and the exiles.

After the lapse of three years, he succeeded in regaining the imperial favor by convincing Constantine that Arius and his views do not conflict with the Nicene Creed. After his return in 329 he brought the whole machinery of the state government into action in order to impose his views upon the Church. 
(wikipedia)

Character of Eusebius
Such was the man who was so crucial to the Christian faith of the Goths - their Arianism - through his choice of the bishop and his powerful support to him.

Eusebius was more of a politician than anything else, and a skilled one. Upon his return, he regained the lost ground resulted from the First Council of Nicaea, established alliances with other groups such as the Meletians and expelled many opponents.
He was described by modern historians as an "ambitious intriguer" and a "consummate political player". He was also described by ancient sources as a high-handed person who was also aggressive in his dealings; he also used his allies to spy on his opponents.
(wikipedia)

The Kingdom of God
Another parable put he forth unto them, saying, The kingdom of heaven is likened unto a man which sowed good seed in his field:
But while men slept, his enemy came and sowed tares among the wheat, and went his way.
But when the blade was sprung up, and brought forth fruit, then appeared the tares also.
So the servants of the householder came and said unto him, Sir, didst not thou sow good seed in thy field? from whence then hath it tares?
He said unto them, An enemy hath done this. The servants said unto him, Wilt thou then that we go and gather them up?
 But he said, Nay; lest while ye gather up the tares, ye root up also the wheat with them.
 Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.
Matthew 13:24-30 KJV


Evaluation of Eusebius of Nicomedia
The writer(s) of the wikipedia describe the impact of Eusebius of Nicomedia in rather solemn colors:

He died at the height of his power in the year 342.

He was so influential that even after his death, Constantius II heeded his and Eudoxus of Constantinople's advice to attempt to convert the Roman Empire to Arianism by creating Arian Councils and official Arian Doctrines.
It was because of Eusebius that "On the whole, Constantine and his successors made life pretty miserable for Church leaders committed to the Nicene decision and its Trinitarian formula." (wikipedia)

As for the Goths...

Mausoleum of Theodoric the Ostrogoth 520 AD (Ravenna)
Its roof is a single 300–ton Istrian stone, 10 meters in diameter. 

because of Wulfila they became Christians and got their own language in writing. The Goths formed powerful states, Visigoths in Hispania and Ostrogoths in northern Italy (Ravenna).

Arian teaching survived among these people for about two hundred years:

Visigoths of Spain accepted Nicene Creed in the Third Council of Toledo in 589.

Ostrogoths were conquered by the famous general Belisarius (500-565) during the time of Justinian the Great and their kingdom was destroyed. Their last king was called Theia and he ruled only for a year 552-553. The remaining people moved to Austria and their nation - and church - was dissolved.

Wulfila in Philostorgius Ecclesiastical History

Photius I the Great (810-893), Patriarch of Constantinople, cites and comments the history written by Philostorgius. His summary paragraphs, epitome, is all that remains of the original Historia Ecclestica and thus of great value.

The quoted English translation of Photius's text is by Edward Waldorf published in the Tertullian Project (I have added subtitles, paragraphs and italics to make it easier reading).


Notes: 

Philostorgius mentions among Roman emperors
- the joint rule of Valerian the Elder and Gallenius from 253 to 260
- Constantius II Roman emperor from 337 to 361

Eusebius of Nicomedia died in 341.

Istros (or Ister) was a River-God of Skythia and northern Europe (the Danube of modern Romania). The most important neighbouring rivers were the Borysthenes (Dnieper) to the east, and Hebros in Thrake to the West. (theoi.com)

According to Philostorgius the parents of Wulfila were taken captives in their home town of Parnassos... Cappadocia Secunda, suffragan of Mocessus. Situated between Ancyra and Archelais, it was formerly important. Another route led to Nyssa. ... Hamilton places it at Kotch Hissar, near Touz Gheul (ancient Lake Tatta), vilayet of Angora; Ramsay ... north-east of this lake on the left bank of Kizil Irmak (ancient Halys), near Tchikin Aghyl.
(Catholic Enc)



EPITOME OF BOOK II


CHAPTER 5

.--He also says that Urphilas brought over as settlers to the Roman territory a large body of persons who had been driven out of their ancient abodes for the sake of their religion. These came from among the Scythians, north of the Ister, and were formerly called Getae, though now they are better known as Goths.

Jesus Christ reaches the Goths
And he asserts that this race of men were brought over to the faith of Christ in the following manner.

While Valerian and Gallienus were administering the empire, a large multitude of Scythians, who lived north of the Ister, made an incursion into the Roman territory, and laid waste a great part of. Europe by their predatory excursions and afterwards having crossed over into Asia, invaded Cappadocia and Galatia. Here they took a large quantity of prisoners, among whom were not a few ecclesiastics; and they returned to their own country laden with spoils and booty.

These pious captives, by their intercourse with the barbarians, brought over a great number of the latter to the true faith, and persuaded them to embrace the Christian religion in the place of heathen superstitions.


Wulfila's background
Of the number of these captives were the ancestors of Urphilas himself, who were of Cappadocian descent, deriving their origin from a village called Sadagolthina, near time city of Parnassus.

This Urphilas, then, was the header of this pious band which came out from among the Goths, and became eventually their first bishop.


Wulfila ordained Bishop of the Goths by Eusebius of Nicomedia
The following was the method of his appointment.

Being sent by the then king of the Goths on an embassy to the court of the emperor Constantine, (for the barbarous tribes in those parts were subject to the emperor,) he was ordained bishop of the Christians among time Goths, by Eusebius and the other prelates that were with him.

Wulfila translated the Bible except for the Book of Kings
Accordingly he took the greatest care of them in many ways, and amongst others, he reduced their language to a written form, and translated into their vulgar tongue all the books of holy Scripture,
with the exception of the Books of Kings, which he omitted, because they are a mere narrative of military exploits, and the Gothic tribes were especially fond of war, and were in more need of restraints to check their military passions than of spurs to urge them on to deeds of war. But those books have the greatest influence in exciting the minds of readers, inasmuch as they are regarded with great veneration, and are adapted to lead the hearts of believers to the worship of God.

Goths in Moesia
This multitude of converts were located by the emperor in the different parts of Moesia, as he thought best, and he held Urphilas himself in such high honour, that he would often speak of him in conversation as the Moses of his day.

but alas, an Arian!
Philostorgius is loud in his praises of this Urphilas and asserts that both he and the Goths who were under his spiritual rule, were followers of his own heretical opinions.

Wulfila as described by Auxentius

The Letter of Auxentius (Jim Marchands translation) tells about Wulfila, his foster-father. It is choke full of theological statements, actually listings of words, epithets of Christ and deep in the controversy against the (Nicean) Homousians.

Here in this I have tried to distil from Auxentius writing sentences that give information about Wulfila's life.

"[Wulfila was] of great propriety, verily a confessor of Christ, a teacher of piety and a preacher of truth. He never hesitated to preach quite openly and very clearly to willing and unwilling alike the one true Cod, the Father of Christ, and the second rank of this same Christ..."

Arian theologian:
"Wherefore he scattered the sect of the Homousians... In his preaching and exposition he asserted that all heretics were not Christians, but Antichrists..."

Fluent in languages:
"Following this and similar doctrines for 40 years flourishing splendidly in the bishopric through apostolic grace, he preached in the Greek, Latin, and Gothic tongues without ceasing in the one and only Church of Christ;"

Student of Scriptures:
"And whoever reads this, let him know that he taught and expounded to us all this concerning the Sacred Scriptures. He also left behind in those very three languages several treatises and many interpretations, for the use and edification of the willing, for his own eternal memory and grace."


Mentor of Auxentius (deacon in Alexandria):
"Whom I am unable to praise sufficiently; yet I cannot be silent, who more than all others am in his debt, in that he worked more richly on me, taking me in early years from my parents as his student, he taught me the Holy Scriptures and made manifest to me the truth. And by the kindness of God and the grace of Christ he reared me bodily and spiritually as a son in the faith."

Bishop of the Goths:
"According to God's providence and Christ's kindness he was ordained -- for the salvation of many -- bishop among the people of the Goths at the age of 30 from the position of lector"

Missioner:
"...teach the people of the Goths, who were living in hunger and deprivation of preaching indifferently; he made manifest to them and taught them to live in accord with the rule of the Gospel, the Apostles and the Prophets, and as Christians to be truly Christians, and thus increased the number of Christians." 


Persecution of Christian Goths at the time of Wulfila:
"...but with Christ's aid and help, they became martyrs and confessors, that the persecutor might be confounded and those who suffered persecution be crowned. He who sought to conquer, blushed as vanquished, and they who were tempted rejoiced as victors."

Wulfila in Consantius II (317-361) court:
"Then after the glorious martyrdom of many servants and handmaidens of Christ, the most holy man, the blessed Ulfilas, having completed seven years in the office of bishop, was driven out by the vehemently threatening persecution from the country of the barbarians with a great host of confessors onto Roman soil and here honorably received by the Prince Constantius, of blessed memory."


Escape of the Goths (to Moesia):
"...so did God free the Goths through the often named confessor of his Holy Only-begotten Son out of the lands of the barbarians and cause them to cross the Danube and to serve Him in the mountains according to the example of the saints."

Death at the age of 70 (383 AD):
"Remaining with his people, not counting those 7 years, 33 years on Roman soil, he preached the truth -- just as he was also an imitator of certain ancient Saints in this matter too -- he completed a space of 40 years, so that he left this life at the age of 70 after the completion of many deeds."

Illness and death in Constantinople:
"After 40 years had been completed, he departed at the imperial behest to Constantinople to a disputation against the ... and he insisted on going in the name of our Lord Jesus Christ, so that they might not teach and infest the churches of Christ dedicated by him to Christ. ...

Having entered into the above city, he immediately began to fall ill, since the impious ones had again reconsidered the situation of the council, so that the more to be pitied as miserable might not be shown to be condemned by their own judgement and be shown to be punishable by the eternal judgement. In which sickness he was taken away in the manner of the Prophet Elisha."

Wulfila - historical sources

Wulfila (Ulfilas) is the Apostle of the Goths and the father of Gothic language and its alphabet.

He was ordained bishop by Eusebius of Nicomedia (died 341), an imperial city in Bithynia in the area of the Black Sea. Eusebius sent Wulfila to work amongst the Goths at the NE borders of Roman empire. After 348 the center of his activities was the city of Nicopolis ad Istrum in Moesia (modern northern Bulgaria).


Arian documents
We know about the life of Wulfila from two rare Arian historical documents

1. Letter of Auxentius of Durorstorum
This valuable document contains the Life of Ulphilas. Auxentius was the foster-son of Wulfila himself and is said to have been a deacon in Alexandria and a follower of bishop Auxentius of Milan (c. 355 – 374). He was actively involved in the Arian controversy and fought against the Nicaean Ambrose with the supoprt of Empress Justina (340-391), the second wife of Emperor Valentinian I.

The Letter of Auxentius (ca 400) was preserved in the margins of a manuscript of De fide of Ambrose. (wikipedia)

The letter includes the Creed of Ulphilas, a unique document about Arian Christianity.

Jim Marchand has put in the Web the Letter of Auxentius together with the Creed of Ulphilas in Latin and with his English translation.


2. Historia Ecclesiastica by Philostorgius
Church historian Philostorgius (368 –439) came from Cappadocia in Asia Minor and lived in the capital city of Constantinople. His book tells the history of Arian Christianity but this has disappeared. Only a summary has survived, the epitome, written by famed Ecumenical Patriarch of Constantinople Photios I the Great (810–893).

All that is known with certainty of Philostorgius is that he was a native of Cappadocia, and was born of humble parentage about the year A. D. 364. It would seem came to Constantinople in his youth to complete his studies; but it is uncertain whether he was educated for the legal or for the ecclesiastical profession. In later life he composed a History of the Church, comprised in twelve books from the beginning of the Arian schism down to the year AD. 425.
(E.Walford)

The interesting text of the epitome is available online as English translation in the Tertullian Project.



Nicaean documents
In addition to these two historical documents also three Nicaean Church historians write about Wuflila in their Church histories

1. Sozomen
Sozomen (400 – 450) wrote his famous Historia Ecclesiastica in Constantinople around 440 - 443.

The work is structured into nine books, roughly arranged along the reigns of Roman Emperors:

• Book I: from the conversion of Constantine I until the Council of Nicea (312-325)
• Book II: from the Council of Nicea to Constantine's death (325-337)
• Book III: from the death of Constantine I to the death of Constans I (337-350)
• Book IV: from the death of Constans I to the death of Constantius II (350-361)
• Book V: from the death of Constantius I to the death of Julian the Apostate (361-363)
• Book VI: from the death of Julian to the death of Valens (363-375)
• Book VII: from the death of Valens to the death of Theodosius I (375-395)
• Book VIII: from the death of Theodosius I to the death of Arcadius (375-408).
• Book IX: from the death of Arcadius to the accession of Valentinian III (408-25).  

(wikipedia)




2. Socrates Scholasticus
Socrates of Constantinople (380-?) completed his Historia Ecclesiastica around 439.

The purpose of the history is to continue the work of Eusebius of Caesarea (1.1). It relates in simple Greek language what the Church experienced from the days of Constantine to the writer's time. Ecclesiastical dissensions occupy the foreground, for when the Church is at peace, there is nothing for the church historian to relate (7.48.7). In the preface to Book 5, Socrates defends dealing with Arianism and with political events in addition to writing about the church.

An English translation is available online in Early Christian Ethereal library and as an e-book from Munseys.com


3. Theodoret of Cyrus 
 Bishop Theodoret of Cyrus (393 – 457) wrote numerous books many of which have survived. He was from 423 to his death 457 an influential bishop in Cyrrhus, Syria (70 km from Aleppo).

The Church History of Theodoret, which begins with the rise of Arianism and closes with the death of Theodore in 429, falls far behind those of Socrates Scholasticus and Sozomen. It contains many sources otherwise lost, specially letters on the Arian controversy; but it is defective in historical sense and chronological accuracy, and on account of Theodoret's inclination to embellishment and miraculous narrative, and preference for the personal. Original material of Antiochian information appears chiefly in the latter books.
(wikipedia)

The works of Theodoret including his Church history are online in the Early Christian Ethereal library.

Wulfila - historical background

Gothic translation of the Bible

Codex Argenteus

In the quiet dignified halls of the Carolina Rediviva Library of Uppsala University, Sweden, is an outstanding memorial to the Apostle of the Goths, Wulfila. There is a permanent display of pages from the Silver Bible, Codex Argenteus, a Byzantine period treasure with an amazing history from Ravenna of the Ostrogoths through many adventures to the safety in the Nordic country, the homeland of the Goths.

The Codex Argenteus Online is a complete digital version of the facsimile edition from 1927, the result of a joint project between Tampere University of Technology and Uppsala University Library.


As in so many other cases, when Jesus Christ, the Word of God, reached the Goths He also gave them literature and often, as this case, also the letters. For in order to translate the first book into Gothic, Wulfila had to first create the alphabet. In Codex Argenteus this great gift to the Goths - the Holy Bible - is beautifully written in their own language and in their own script literally in silver letters.

"In March 1995, parts of the Codex that were on public display in Carolina Rediviva were stolen. The stolen parts were recovered one month later, in a storage box at the Stockholm Central Railway Station. The details of the Codex disappearance and wanderings for a thousand years remain a mystery; it is unknown whether the other half of the book may have survived."
(wikipedia)

Ulfilas, or Gothic Wulfila (also Ulphilas. Orphila) (ca. 310 – 383), bishop, missionary, and Bible translator, was a Goth or half-Goth and half-Greek from Cappadocia who had spent time inside the Roman Empire at the peak of the Arian controversy.

Ulfilas was ordained a bishop by Eusebius of Nicomedia and returned to his people to work as a missionary. In 348, to escape religious persecution by a Gothic chief, probably Athanaric he obtained permission from Constantius II to migrate with his flock of converts to Moesia and settle near Nicopolis ad Istrum, in what is now northern Bulgaria. There, Ulfilas translated the Bible from Greek into the Gothic language. For this he devised the Gothic alphabet. Fragments of his translation have survived, notably the Codex Argenteus held since 1648 in the University Library of Uppsala in Sweden. A parchment page of this Bible was found in 1971 in the Speyer Cathedral.

His parents were of non-Gothic Anatolian origin but had been enslaved by Goths on horseback. Ulfilas converted many among the Goths, preaching an Arian Christianity, which, when they reached the western Mediterranean, set them apart from their Orthodox neighbors and subjects.
(wikipedia)

Moesia
The life of Wulfila takes us thus to Moesia where we first met the Goths after they had crossed in mid 3rd century Danube raiding this region and taking especially female captives. These women brought with them in their hearts Christ to the pagan Gothic villages and families.

Later on Goths again captured slaves from neighbouring regions and so the parents of Wulfila were taken from Anatolia to Moesia. In this way this became the homeland of the boy who later was to became the Apostle of the Goths.


Thervingi

Mureş-Chernyakhov culture (organge)
Götaland in Sweden (green)
Island of Gotland (red)
Wielbark culture (red)
Late Roman empire (lilac)
(wikimedia)

The Thervingi, Tervingi, or Teruingi (sometimes pluralised "Tervings" or "Thervings") were a Gothic people of the Danubian plains west of the Dnestr River in the 3rd and 4th Centuries CE. They had close contacts with the Greuthungi, another Gothic people from east of the Dnestr River, as well as the Late Roman Empire (or early Byzantine Empire). Archaeologically they correspond to the Sîntana de Mureş- Chernyakhov culture, together with the Greutungi. (wikipedia)

In the fourth century the mighty Thervingi tribes were divided among those who followed Christ and those who followed the ancient pagan idols.  Athanaricus (died 381) or Athanareiks "King for the Year", was the king of many Therving tribes. His rival Fritigernus (died 380) was a military chieftain of the Thervings. 


Gothic Wars
In the crucial times in early 3rd century when Christ was fighting for the soul of Rome, Constantine the Great ordered that his soldiers helmets and shields should carry the sign of Christ, labarum. His competitor for the rule of Rome was Licinius who was an ardent follower of the ancient pagan gods.

In rather similar manner, during the critical time of the Gothic Wars (367-369, 376-382) when Emperor Valens (328-378) had attacked the Thervingi in the Danube plains in 367, King Athanaricus presented the old Gothic paganism and persecuted his Christian tribesmen to whom his rival, the brave Fritigernus belonged.


Huns in the horizon
Emperor Valens adventures with the Goths were playing with fire. Fritigernus led his people to Christ and he adopted the Arian Christology that Valens himself preferred at these years of the Ecumenical councils of Nice-Constantinople (325, 381). But things did not go well for the Romans...

The Thervingi remained in western Scythia (probably modern Moldavia and Wallachia)until 376, when one of their leaders, Fritigern, appealed to the Roman emperor Valens to be allowed to settle with his people on the south bank of the Danube. Here, they hoped to find refuge from the Huns. Valens permitted this.

However, a famine broke out and Rome was unwilling to supply them with the food they were promised nor the land; open revolt ensued leading to 6 years of plundering and destruction throughout the Balkans, the death of a Roman Emperor and the destruction of an entire Roman army.

The Battle of Adrianople in 378 was the decisive moment of the war. The Roman forces were slaughtered; the Emperor Valens was killed during the fighting, shocking the Roman world and eventually forcing the Romans to negotiate with and settle the Barbarians on Roman land, a new trend with far reaching consequences for the eventual fall of the Roman Empire. (wikipedia)

Such was the environment in which Jesus Christ conquered the Goths and gave them their language in writing. This was to be of great significance soon as the Fall of Rome and the end of the classical world was fast approaching. It has also lasting importance to the history of Iberian Peninsula and  Christ reaching Spain as well as to the Byzantine history of northern Italy.

Oh Arius, you Darnel!

But while his men were sleeping, his enemy came and sowed tares among the wheat, and went away.
Matthew 13:25 

Arianism was among the major issues discussed at the Council of Nicaea in 325. At that time there was no commonly adopted doctrine about anything in the Kingdom of God. Persecuted Christians did not have the chance to come together to talk about the content of their faith. The Scriptures were a gentle guide drawing the line between Judaism, Christianity and paganism but as we know, they raise as many questions as they answer.
Constantine I had learned to his dismay that bitter disputes existed among the Christians also about the most fundamental issues, such as Who is God. How could such a confused religion unite the people of the Empire under One God and one Caesar?

Theologians had written many treaties that tried to solve the breaking up of the theological concept of One God of Israel because of what had happened in Jesus Christ. Some of them were working on the line that was eventually accepted at Nicaea: God is One Trinity. This paradoxical close-up of One God has ever since been the fundamental teaching of Christian churches.

Trinity
The concept of Trinity is not really clear in the classic wording of the Nicene Creed:

We believe in one God, the Father Almighty, Maker of all things visible and invisible. 
And in one Lord Jesus Christ, the Son of God, 
begotten of the Father [the only-begotten; that is, of the essence of the Father, God of God], 
Light of Light, 
very God of very God, 
begotten, not made, 
being of one substance with the Father;
By whom all things were made [both in heaven and on earth];
Who for us men, and for our salvation, came down and was incarnate and was made man;
He suffered, and the third day he rose again, ascended into heaven;
From thence he shall come to judge the quick and the dead.
And in the Holy Ghost.

Faith in One God, Monotheism, the pillar of Judaism (Shema Israel) and absolute foundation of Islam.

They have it easy.

The section on Lord Jesus Christ is highly complex language and difficult to understand, at the limits of what human languages - even the delicate classical Greek - can express.


Arianism
In the Kingdom of Heaven there was a more sensible solution proposed by presbyter Arius (250–336) from the theological capital of Alexandria.

Faith in One God.

This must be the unshakeable foundation of true faith.

So why let this Jesus guy, admittedly a human born in the little town of Bethlehem, to break up this teaching of the One Majesty, God of Israel?

Arius relied on the holy Scriptures that underline that God is One and he noticed that Jesus himself says

"You heard me say, ‘I am going away and I am coming back to you.’ If you loved me, you would be glad that I am going to the Father, for the Father is greater than I."
John 14:28

Presbyter Arius began to look at the very beginning of everything and concluded that there must have been a time before Jesus Christ existed since he is called Son of God.

It is obvious, is it not, at least according to our human language and logic that if there is a Father and He has a Son, the Father was before the Son.


Wikipedia article summarizes all this nicely:

"Arius taught that God the Father and the Son did not exist together eternally.
He taught that the pre-incarnate Jesus was a divine being created by (and therefore inferior to) God the Father at some point, before which the Son did not exist.
In English-language works, it is sometimes said that Arians believe that Jesus is or was a "creature", in the sense of "created being". Arius and his followers appealed to Bible verses such as where Jesus says that the father is "greater than I" (John 14:28), and says "The Lord created me at the beginning of his work" (Proverbs 8:22) although this verse is now generally held by trinitarians to refer to some concept of "wisdom" rather than to the Son of God.
Of all the various disagreements within the Christian Church, the Arian controversy has held the greatest force and power of theological and political conflict, with the possible exception of the Protestant Reformation. The conflict between Arianism and Trinitarian beliefs was the first major doctrinal confrontation in the Church after the legalization of Christianity by the Roman Emperors Constantine I and Licinius."
Quoted from wikipedia


Tares among the wheat (darnel)
The teaching of Arius was not only a powerful catalyst in the development of Church teaching about Trinity that challenged the greatest minds in early Byzantine period from St Athanasius and St Augustine to the Cappadocian Fathers.

It was also tares among the wheat that spread among the wheat in the fields of Christ. The most significant believers who followed Arian teaching were the fearsome Goths approaching the borders of the Roman empire and eventually breaking in with devastating consequences to the classical world in events that changed the history of the world.

The growth of the Kingdom of Christ in Europe at these turbulent times was strongly influenced by Arian Christology from the regions of modern Yugoslavia all the way along the northern borders of Roman empire and to Spain.

A key person in this sowing of the darnel was Wulfila who brought many pagan Gothic tribes to Christ the Created One.


Arianism today
Because the teaching of Arius makes sense - of course Father is greater than Jesus, God is eternal, invisible, One - probably quite many baptised Christians today have similar ideas about the relationship between God and Christ at the back of their heads even when confessing the Nicene Creed by their mouths.

Trinity is a tough doctrine because it is so paradoxical and does not fit into the mighty power of our brains!

Go ask St Augustine if you do not agree with me on this!