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The Council of Nicaea

The Council of Nicaea: Resolving the crisis in early Christianity

A fresco in the Vatican depicting the Council of Nicaea 325 | Wikimedia | Public Domain

Crisis in the Christian Church

Before the Council of Nicaea in AD 325 was called, a crisis had begun to appear within the Christian Church revolving around one of the most important beliefs of Christianity, the Holy Trinity. Various interpretations of it had spread to congregations throughout the empire threatening a schism in the early Christian Church. The council assembly was set up with one major aim; to bring about unity within the Church made up of disparate denominations and resolve the crisis. This ambitious undertaking attracting hundreds of delegates was the brainchild of Constantine I (Emperor from 306 – 337 AD, the first Roman Emperor who converted to Christianity. The debate centred on two influential ideologies with differing beliefs about the Holy Trinity, one of which by the closing of the council would be castigated as ‘heretical’ and banished.

The First Ecumenical Council

The Council of Nicaea was an assembly of religious delegates arranged by Constantine I between May to August AD 325, which defined the Christian Church doctrine and beliefs, particularly relating to the holy trinity and relationship between God and Jesus, as is still accepted today. Held in a region of the then Roman province in the northwest of Asia Minor in the ancient city of Nicaea (now in Turkey) it was the first council in the history of the Christian church that was intended to address the entire body of believers of the Christian faith. The assembly was convened by Emperor Constantine, after recommendation by the bishop Hosius of Corduba, to resolve the growing controversy of Arianism, one of several theological beliefs that held that Christ was not divine but was a created being.

The one purpose of the Council was to resolve such disagreements over the nature of the ‘Son’ in his relationship to the ‘Father’ and whether the former had been ‘begotten’ by the Father from his own being.

Controversial views such as did the ‘Son’ have no beginning or was he created, dominated the theological debate. This history-making assembly was the first occasion where technical aspects of the Christian faith were discussed and debated and led to the beginning of the first seven ecumenical councils in the history of Christianity.


Before the Council of Nicaea, the ‘Trinity’ doctrine at the time of the New Testament (the second division of the Christian biblical canon) was formulated as an attempt to understand the relationship between Jesus and God. From the 1st to the 4th centuries various church leaders argued over the doctrine, the most significant developments being articulated by Christian sects that questioned the established view of the Trinity which defined God as a ‘trinity of persons: the Father, the Son, and the Holy Spirit’ but that they were three distinct persons, yet are all the one, God.

Some leaders of Christian sects did not believe in the Trinity at all and it was this myriad of differing beliefs, threatening to undermine the Christian Church and unify believers that concerned Constantine I.

Religious Civil-War

Plagued by the threat of a religious schism Constantine invited bishops from within the Roman Empire. where delegates could debate opposing views relating to ecumenical matters concerning the Christian faith. Constantine's aim in convening the council was to deliver consensus in the Christian church through the assembly representing all Christendom and Christian religions.

Before the council of Nicaea, the Christian world knew several competing Christological ideas such as Adoptionism (the belief that Jesus was an ordinary man), Sabellianism (the Father, Son and Holy Spirit are three different aspects of God) and Arianism (Son of God is not co-eternal with God the Father and is therefore subordinate) while other sects didn’t believe in Trinitarianism at all.

What began as an academic theological debate spread to Christian congregations throughout the empire, threatening a schism in the early Christian church. Constantine desperately wanted to bring about unity within the Church to resolve the crisis and urged the adoption of a new creed.


There is debate about how many priests and delegates attended the council meeting with some numbers ranging from a conservative estimate of 300 to a more ambitious figure of 1000. Most came from every region of the Roman Empire including Britain. The bishops were given free travel and board, paid through public funds, and could also bring ‘guests’ usually from a variety of religious orders. With such generous hospitality offered by Constantine, it is not surprising that attendees could have surpassed over 1800.

Rival ideologies

The two principal players on opposite sides of the theological tracks at were arch-rivals Arius and Athanasius, both priests of Alexandria in Egypt. The two Christian theologians held passionately differing views and beliefs surrounding the relationship between God and Jesus, relating to God the Father and God the Son. These opposing factions had been at loggerheads with each other for 55 years and were now seen as a threat to a Christian Church striving for unity.

Arianism, attributed to Arius (256 AD – 336 AD ) was an elder and minister in the Christian church and held the belief that the Son of God was not co-eternal with God the Father and instead distinct from the Father, therefore subordinate to him. Athanasius on the opposing side of the ecumenical ring was the defender of the Nicene Theology for orthodox Christianity against the alleged ‘heresy’ of Arianism which rejected the divinity of Christ.

The debate

Constantine was no theologian himself and relied on the religious expertise of the invited bishops to investigate the issues at hand. Many books such as the 27 gospels of the New Testament were referenced as source material to come to conclusions about such important matters as the nature of the Holy Trinity and an accepted definition of the relationship between God, the Son and the Holy Spirit. Was Jesus a divine character distinct from God the Father or were all three of the same God? At the time the gospels of Matthew, Mark, Luke and John were among at least two dozen more analysed to determine a consensus on the question of the divinity of Christ; an agreement that Constantine desperately sought to bring about unity in the fractious Christian Church. The bishops looked at passages like Matthew:28 and John 14, in which the latter passage talks about God the Father and the Holy Spirit in the same verse. Such analysis was focused on looking at distinctions between the Father, the Son and the Holy Spirit to understand the relationships.

Date of Easter controversy

One important problem the council wanted to come to an agreement on was agreeing on the day Easter falls, which even centuries after the issue was first raised during the Nicaean Council still remains unresolved.

Easter is linked to the Jewish Passover on the understanding that Jesus was crucified at the time of the Passover, an event celebrated every year to commemorate the Jews’ liberation by God from slavery in ancient Egypt. The controversy over the correct date for Easter is due to the fact that the date cannot be separated from the Passover period and debates began as early as the 2nd Century due to this obstacle.

The Passover was calculated by Jews based on cycles of the moon. The Council declared that Easter was always to be held on a Sunday but didn’t link it to a particular phase of the moon. A dispute arose as to the determination of the Sunday itself since Sundays can occur on any date of the month, Discussion and disagreement over the best method for computing the date of Easter Sunday has been ongoing and unresolved for centuries. Different Christian denominations continue to celebrate Easter on different dates with Eastern and Western churches being an example. Today’s differences are more to do with the utilization of the different calendars (Julian – East v Gregorian –West).meaning that Easter will fall on different dates.


Athanasius I of Alexandria (296–373) also known as Athanasius the Great was in direct conflict with Arius whose theological views were rooted in Alexandrian Christianity. He spent most of his life confronting Arianism which had its supporters at the Council as well as being an ideology shared by other Christians in the Empire, who believed that Christ was the divine Son of God, and made, not begotten. One passionate ally of Arius was Eusebius of Nicomedia, an Arian priest.

Athanasius, as a follower of the ‘Homoousian’ ideology, held the opposing view that God the Father and God the Son were of the same substance and therefore having no beginning. Homoousian is a Christian theological term associated with the Nicene Creed which describes Jesus as ‘same in being’ or ‘same in essence’ with God the Father. During the debate and analysis of passages written by Arius some bishops believed the writings were blasphemous leading to what was considered to be the ‘Arian controversy’. The debate became so heated and volatile that it is alleged that Arius was struck in the face as the main bone of contention continued to be hinged on the difference between Jesus being ‘born’ or ‘created’ and in the case of Arianism, seen as a finite being.

Supporters of Arius referred to biblical statements such as ‘the Father is greater than I’ (John 14.28) to back up their claims. Athanasius countered this viewpoint declaring that the Arian view was in contravention of the Scriptures and that the ‘Son had no beginning, but had ‘eternal derivation’ from the Father’.

After a month of debating the Council declared that the Son was true God, co-eternal with the Father, which contributed to a consensus between most of the bishops resulting in the Creed of Nicaea. Arianism was declared heretical and Arius banished.

The Nicene Creed (325 AD)

The Nicene creed pushed the idea that Jesus was one with the Father and made the language strong enough so that no-one could confuse an interpretation of Jesus’ relationship with God, that he was begotten later. Part of the reason why the wording was made explicit was due to a perception that ambiguity was dangerous and could undermine the Christian Church. In other words, the Council were concerned that if there was a view that Jesus on the cross was just a man, then no man would atone for anyone’s sins. The belief in Jesus dying for the sins of humanity was and is seen as central to Eastern and Western Christianity. With Arianism rejected (for the time being), great leaders such as Athanasius, the 20th bishop of Alexandria, together with Alexander of Alexandria and bishops such as Eustathius of Antioch all adhered to the Homoousian position.

Debate reversals

The end result of the Council of Nicaea was seen as a success by Emperor Constantine. From his point of view, he had brought priests and delegates together from different political and religious factions with diverse opinions, to agree on a single creed, he had exiled dissenters and unity was restored on a superficial basis.

This wasn’t quite as clear cut as Constantine had hoped as a few months after the council he found himself having to exile Eusebius a prelate who had signed the creed but who had continued to refuse to condemn Arius.

Spared exile, Eusebius worked within the court as a known confirmed Arian and used his position to try and soften Constantine’s views on Arianism on an almost daily basis. The scheme worked as over time Constantine who wanted harmony in his empire softened his approach to his more hardline view of Arianism as being heretical and even began to see the possibilities of ‘coexistence’ between opposing theological ideologies.

The Arian doctrine began to gain strength in the Empire after having been discredited and deemed heretical. The reprieve for the Arian doctrine would spread out throughout the empire, eventually influencing Gothic tribes and cementing Arian Christianity as the basis for Christianity for the Germanic tribes in the region of northern Europe and were to later play a part in the fall of the Roman Empire.

Conclusion and legacy

The Council did not completely solve the problems it was convened to discuss and conflict continued. Pagan powers within the Empire re-established themselves and Arianism continued to spread and be the subject of debate. The Nicaean Council, the agreed creed of today is still a source of controversy in the world of Christianity and its many denominations today.

As a marker in history where the Council was the first universal gathering of Christian priests, bishops and scholars to discuss ecumenical matters, it was one of the most important moments in the Christian Church. The Council of Nicaea is recognised by virtually all ‘mainstream’ Christian denominations (to varying degrees) including, Roman Catholic, Eastern Orthodox, Oriental Orthodoxy, Anglican and Lutheran churches.