The central issues decided at the Council of Nicaea

The first ecumenical council in the history of the Church (held in Nicaea in 325) was not convened for minor issues! In the time of the apostles, the Council of Jerusalem (Acts 15) had to settle the decisive question concerning the admission of Christians from the non-Jewish world. It decided they did not need to be circumcised and obey the law of Moses to become Christians. Subsequently, numerous local councils were held from the second century onwards to resolve issues of ecclesiastical discipline or doctrinal points under debate.

The year is 325 and the persecutions are over. Emperor Constantine I has restored political peace to the empire. But he hears of a serious doctrinal disagreement between the bishop of Alexandria and one of his priests, Arius, which broke out in 318. A local council was unable to resolve it.

The affair escalated. The emperor intended to establish religious peace. He convened an ecumenical council in Nicaea, now Iznik, in Turkey. It brought together more than 300 bishops—the vast majority from the empire and 90% of them Greek-speaking—but also deacons, theologians, and philosophers, some of whom were not Christians. The emperor took charge of all the logistics. The decrees had to be made known and applied throughout the inhabited world (oikumene).

The 20 canons they promulgated dealt with questions of canonical discipline. There was also the question of a common date for the celebration of Easter for Christians: all had to break with the date of the Jewish Passover, which some communities still followed. The question of the divine nature of the Son, rejected by Arius, occupied the major part of the debates.

This confrontation called into question the very heart of the Christian faith: salvation through Christ, true God and true man. Is Jesus, the Son of God, a creature of God, as Arius maintains, or God himself, who alone can save? Arius denied the eternity of the Son, and made him a creature subordinate to the Father, so as not to overshadow the oneness and divinity of God.

To express the unity between the Father and the Son, the key word of “consubstantial” (homoousios in Greek) is intended to be explanatory: the word does not add any content to the biblical data. However, the words ousia and homoousios will generate long debates. The meaning that the philosophical word ousia (nature, substance) had at Nicaea created friction—in the case of Basil and Gregory of Nyssa, for example—with the competing use of the word hypostasis.

Moreover, the Christological heresy of Arius that was confronted at Nicaea called into question the biblical vision of the human being, and opened up a possible anthropological heresy.

The use of philosophical terms is in no way a disavowal or replacement of biblical language. Moreover, the creed mostly uses biblical language, taken mainly from John: Jesus is God (Jn 1:1), light (Jn 8:12; 9:1-7), true God (1 Jn 5:20), begotten (Jn 1:13), through whom all things were made (Jn 1:3; Col 1:16 and 1 Cor 8:6).

And it uses formulations that explain the common ousia of the Father and the Son: to “begotten,” the creed adds “not made,” to respond to the theses of Arius. With the same intention, it specifies “light from light” and “true God from true God.”

By taking up the biblical terms and explaining them in philosophical terms in the ecumenical definition of the faith, the council turned over a new leaf. It consecrated the fruitfulness of theological effort in the interpretation of Scripture.

Nicæa recognizes the authority of the Church, gathered in an ecumenical council, to specify the content of the Christian faith by a dogmatic definition that manifests the progress made in the explanation of what has been revealed.

Faith is a truth to be believed and understood. The great decisions concerning faith must be taken in ecumenical council, with the representatives of the whole inhabited earth, and not in a sectorized manner. The tension between the local and the global, between unifying ecumenism and legitimate autonomy, is still an important issue within and between churches.

Although we are in a different era, we still need to consider the rightful autonomy of temporal authority and the place of the Church in civil society.

The Nicene heritage is also the interweaving of political and religious powers. This can be seen in the role played by the emperor in the logistical organization of the event and its consequences. In the context of the Roman era, the involvement of the temporal in the religious was quite common. Constantine inherited this.

Although we are in a different era, we still need to consider the rightful autonomy of temporal authority and the place of the Church in civil society. But it’s also up to us to interpret why and how the political and social spheres regularly appropriate the figure of Christ, even outside of a religious context, by making him play a role derived from his teachings (prophet, revolutionary). This popularization of Jesus is also a roundabout way of erasing his divine identity.

The Council of Nicaea anathematized Arius and formalized the separation between Jews and Christians. But it also laid the foundations for entering into dialogue with contemporary cultures, particularly in a multicultural and multireligious world.

Nicaea was experienced in a Christian context and yet it took a position with respect to Judaism and the beliefs of Antiquity. Contrary to popular belief, Judaism conceives of the corporeality of God in many ways. A hermeneutic of the Nicene Creed sheds light on its anchoring in the First Covenant. If theology is developed in the intersection of faith and culture, this is not without implications for the proclamation of the gospel in new contexts.

In the fifth century, in Rome, the Council of Nicaea could be reread to justify the universal service of unity and the primacy of the apostolic see of Rome in its relationship with the other sees. For its part, the East emphasized that Nicaea had made it possible to develop and structure conciliarity and collegiality to strengthen Christian unity.

This dual reception can be examined from both upstream and downstream perspectives. Upstream, the practice is heir to synodal practices of the second century that sought to define the common faith according to criteria that remain relevant to thinking about the unity of the Church. Downstream, Nicaea can inspire today's ecumenical research, even if it has also been a sign of contradiction in the history between East and West.

Indeed, the authority of Nicaea is recognized in ecumenical dialogue, even if it doesn’t settle all the doctrinal questions that will arise later, including that of the Filioque. The Council sought to combine diversity and unity in cultural and theological approaches to the Christian faith. The person of Jesus is the foundation, the cornerstone of the Church and of the unity of Christians, who confess him as true God, born of God, and true man.