Opportunity and Challenge for Ecumenism

Cardinal Kurt Koch

Prefect of the Dicastery for Promoting Christian Unity

In the midst of the 2025 Jubilee Year — a Holy Year proclaimed by Pope Francis to rekindle Christian hope — the 1,700th anniversary of the first Ecumenical Council in Church history, held in Nicaea in 325, will also be celebrated. This anniversary has significant ecumenical dimensions, made evident by the fact that the Holy Father has expressed a desire to travel to Nicaea to commemorate the event together with the Ecumenical Patriarch, Bartholomew i. The Faith and Order Commission of the World Council of Churches is also preparing for this celebration.

The Common Profession of the Christian faith

Of particular ecumenical relevance are the doctrinal issues addressed by the Council, which are summarised in the “Declaration of the 318 Fathers”. With this Declaration, the Fathers professed their faith in “one God the Father all powerful, maker of all things both seen and unseen. And in one Lord Jesus Christ, the Son of God, the only-begotten begotten from the Father, that is from the substance of the Father, God from God, light from light, true God from true God, begotten not made, consubstantial with the Father, through whom all things came to be, both those in heaven and those in earth”. In the Letter of the Synod to the Egyptians, the Fathers announced that the primary subject of discussion was that Arius and his followers were enemies of the faith and opposed to its law. They “unanimously agreed that anathemas should be pronounced against his impious opinion and his blasphemous terms and expressions which he has blasphemously applied to the Son of God”.

These declarations provide the context for the Creed formulated by the Council, which professes faith in Jesus Christ as the Son of God, “consubstantial with the Father”. The historical backdrop is that of a violent dispute which broke out in Christianity at the time, especially in the Eastern part of the Roman Empire. In the early fourth century, the Christological question had become a central issue of Christian monotheism. The controversy mainly revolved around how to reconcile the profession of Christian faith in Jesus Christ as the Son of God with the equally Christian faith in one God, in accordance with the monotheistic confession.

Arius of Alexandria, a theologian, advocated especially for a strict monotheism in line with the philosophical thought of his era and, to maintain such a strict monotheism, he excluded Jesus Christ from the concept of God. From this perspective, Christ could not be “Son of God” in the real sense of the word, but merely an intermediary whom God uses for the creation of the world and for his relationship with human beings. The Council Fathers rejected this model of strict philosophical monotheism that Arius spread, and they set it against the creed according to which Jesus Christ, as Son of God, is “consubstantial with the Father”.

With the word, “homoousios”, the Council Fathers sought to express the deepest mystery of Jesus Christ, which Sacred Scripture testifies to as faithful Son of the Father, to whom he is intimately united in prayer. In fact, it is in prayer that Jesus most clearly appears as the Son of the heavenly Father. In the New Testament, predominantly in the Gospel of Luke, Jesus is presented in his earthly life as the Son of God in constant prayer, whose existence centres on dialogue with the heavenly Father and who lives with Him in profound unity. Jesus lived in and from prayer to such an extent that his entire life and mission can be defined as one continuous prayer. Without this prayerful attitude, one cannot understand Jesus Christ. This is precisely what the Council Fathers of Nicaea sensibly realized, using the term “homoousios” to offer the correct interpretation of Jesus’ prayer and a deeper interpretation of his life and death, which were marked at every moment by dialogue with the Father.

With the word “homoousios”, the Council of Nicaea did not “Hellenize” biblical faith, submitting it to an unrelated philosophy, but rather, embraced the incomparable newness made visible in Jesus’ prayer to the Father. It was rather Arius who conformed Christian faith to the philosophical thought of the time, while the Council of Nicaea used the philosophy of that era to express what was characteristic of the Christian faith. In the Nicene Creed, the Council again expressed itself as Peter and with Peter at Caesarea Philippi: “You are the Christ, the Son of the living God” (Mt 16:16).

The Council’s Christological creed became the base of the common Christian faith. The Council takes on great importance especially because it took place at a time when Christianity was not yet torn by the numerous divisions that would later emerge. The Nicene Creed is shared not only by the Eastern, Orthodox and Catholic Churches, but also by the ecclesial Communities born of the Reformation; its ecumenical relevance must therefore not be underestimated. In fact, to restore the unity of the Church, there must be agreement on the essential contents of the faith, not only among today’s Churches and ecclesial Communities, but also with the Church of the past, in particular, with her apostolic origin. The unity of the Church is based on apostolic faith, which is transmitted and entrusted to each new member of the Body of Christ in baptism.

The Foundation of Christological Spiritual Ecumenism

Since unity can only be found in a shared faith, the Christological confession of the Council of Nicaea is the cornerstone of spiritual ecumenism. This is obviously a pleonasm. Christian ecumenism is either spiritual or it is not ecumenism. This is why the Second Vatican Council’s Decree on ecumenism defines spiritual ecumenism as “the soul of the whole ecumenical movement” (Unitatis Redintegratio, 8). That was already evident at the start of the ecumenical movement, with the introduction of the Week of Prayer for Christian Unity, itself an ecumenical initiative. The ecumenical movement was a prayer movement from the very beginning. It was prayer for Christian unity which paved the way for the ecumenical movement.

The centrality of prayer shows that ecumenical efforts are above all a spiritual task, undertaken with the conviction that the Holy Spirit will show us the way and bring to fruition the ecumenical work. This is especially true when spiritual ecumenism is perceived and acted upon as Christological ecumenism, for which the Council of Nicaea is a solid foundation. In fact, the heart of Christian ecumenism resides in the shared conversion of all Christians and all Churches to Jesus Christ, in whom we have already been given unity. Christian ecumenism can progress in a credible manner only if Christians return together to the source of faith, which can be found only in Jesus Christ, as the Council Fathers professed in Nicaea.

In this way, Christian ecumenism corresponds more profoundly to the will of the Lord, who, common to all Christians, in his priestly prayer asked for the unity of his disciples: “that they may all be one” (Jn 17:21). What’s striking about Jesus’ prayer is that he does not command nor demand unity among his disciples; rather, he prays for unity, turning to the heavenly Father. This prayer reveals what the ecumenical search, aimed at restoring unity in the light of faith, must consist of. Christian ecumenism cannot be but the adherence of all Christians to the Lord’s priestly prayer, and it becomes such when Christians make this strong desire for unity their own. If ecumenism is not limited to an interpersonal and philanthropic dimension, but has a truly Christological inspiration and foundation, then it cannot be but participation in Jesus’ priestly prayer. The deeper meaning of spiritual ecumenism as Christological ecumenism is that we all allow ourselves to be participants in Jesus’ prayer to the heavenly Father, and therefore become one. The interior dwelling of Christian unity can be nothing if not Jesus’ prayer.

The Council’s Lasting Relevance

If we keep these various aspects of the Council of Nicaea’s Christological confession in mind, the need to celebrate its 1,700th anniversary in ecumenical communion with all the Christian Churches and to rediscover and highlight once more its confession of faith in Jesus Christ, becomes clear. This need, an important imperative of present-day ecumenism, becomes apparent for an additional reason. If we take an honest look at the current context of faith, we must recognize that we are in a similar situation to that of the fourth century, because we are experiencing a strong reawakening of Arian leanings.

Already in the ’90s Cardinal Joseph Ratzinger recognized “new Arianism” as the real challenge modern Christianity is facing. The spirit of Arianism is especially perceptible in the fact that, even today, many Christians are sensitive to all the human dimensions of Jesus of Nazareth, but they have problems with the Christological confession, and therefore, with the Church’s Christological faith, according to which Jesus of Nazareth is the only Son of the Heavenly Father. Nowadays, in the Church and with ecumenism, it is often very difficult to glimpse the face of God himself in Jesus the man, and to profess him as Son of God, because one tends to see him as merely human, no matter how utterly good and exceptional.

But if Jesus, as many Christians today believe, were only a man who lived 2,000 years ago, then he would be irremediably relegated to the past, and only our human memory would be able to bring him to the present, more or less clearly. In that case, Jesus could not be the only Son of God since God himself is present among us. We can profess that Jesus is “consubstantial with the Father” only if the confession of the Church — according to which God himself became man and Jesus Christ is true God and true man and thus participates in God’s presence, which embraces every age — is true.

The Christian faith today stands or falls with the Christological confession of the Council of Nicaea. Therefore, concerning ourselves with this Council is important, not only on a historical level. Its creed remains current, especially given the situation of faith today. And rekindling her Christological confession is a challenge which must be faced in ecumenical communion.

The Search for a Common Date for Easter

The Council of Nicaea is important from an ecumenical perspective because, in addition to the Christological confession, it dealt with disciplinary and canonical matters which, presented in 20 canons, offer a good overview of the problems and pastoral concerns of the Church at the beginning of the fourth century. They are matters regarding the clergy, some jurisdictional disputes, cases of apostasy, and the situation with the Novations, the so-called “pure ones”, and with the followers of Paul of Samosata.

The most important pastoral matter was the date of Easter, which shows that it was already controversial in the early Church and that there were different dates in existence: in Asia Minor especially, Christians celebrated Easter at the same time as the Jewish Passover, the 14th of Nisan, which is why they were known as Quartodecimans. Instead, the Christians known as “Protopaschites”, especially in Syria and Mesopotamia, celebrated Easter on the Sunday following the Jewish Passover. In light of this situation, the Council of Nicaea is credited with having found a uniform norm, expressed in the Letter to the Egyptians: “We also have good news for you that we have harmonized our opinions on the subject of the most holy feast of Easter, which has been happily settled through your prayers”. That meant that the feast of Easter would have to be celebrated in accordance with the Romans’ celebration.

In the history of Christianity, a new situation developed in the 16th century, when Pope Gregory xiii, with a key reform of the calendar, introduced the so-called Gregorian calendar, which placed the Easter celebration on the Sunday following the first full moon of spring. While the Western Churches continue to calculate the date of Easter according to that calendar, the Eastern Churches still largely use the Julian calendar, which was also the basis for the Council of Nicaea.

Although various proposals for a shared date for Easter have been discussed since then, the matter has not yet been resolved. Vatican Council ii also addressed this urgent pastoral challenge in an appendix to the Constitution on the Sacred Liturgy Sacrosanctum Concilium promulgated in 1963, affirming a desire to recognize “the importance of the wishes expressed by many concerning the assignment of the feast of Easter to a fixed Sunday and concerning an unchanging calendar”. The Council affirmed that it “would not object if the feast of Easter were assigned to a particular Sunday of the Gregorian Calendar provided that those whom it may concern, especially the brethren who are not in communion with the Apostolic See, give their assent”. Pope Francis has expressed the same spirit of openness more than once.

The 1,700th anniversary of the Council of Nicaea provides a special opportunity to revisit the matter of the date of Easter, especially because in 2025, it will land on the same day, 20 April, for both Eastern and Western Churches. The ecumenical community’s renewed desire to welcome the grand anniversary of the Council as an opportunity to resume and intensify efforts to find a shared date for Easter, is therefore understandable.

Synodal Style

In line with an ecumenical perspective, the Council of Nicaea is particularly relevant also because it shows how the then heated discussion about the orthodox Christological confession and the pastoral-disciplinary matter of the date of Easter were discussed and decided upon in a synodal style. Church historian Eusebius of Caesarea, who was one of the Council Fathers and who recognized a new Pentecost in the Council of Nicaea, expressly highlighted that the first ministers of God had assembled at the Council “from all the churches which abounded in Europe, Africa, and Asia”. The Council of Nicaea, therefore, on the level of the universal Church, can be considered as the beginning of the synodal way of discussing matters and making decisions.

The 1,700th anniversary of the Council of Nicaea should thus be seen also as an invitation and a challenge to learn from history and better understand the synodal mentality, anchoring it in the life of the Church. Today’s revitalization of the Church’s synodal dimension is not new; rather, it can be linked back to the synodal traditions of the early Church. Already the famous Father of the Church, John Chrysostom, explained that “Church” is a name “standing for ‘walking together’” and that Church and Synod are therefore “synonyms”.

We can learn a lot from each other in this field, including in ecumenical conversations, since synodality developed in different ways in the various Churches and ecclesial communities. This was demonstrated for example, by the international ecumenical Symposiums organized by the Institute for Ecumenical Studies of the Pontifical University of Saint Thomas Aquinas in preparation for the Synod of Bishops on the concepts and experiences related to synodality in Eastern and Western Christian Churches, and entitled “Listening to the West” and “Listening to the East”. These meetings have shown in a significant way that the Catholic Church can be enriched by theological thought and by the experiences of other Churches in the effort to rekindle a synodal way of life and to strengthen corresponding structures. They have also shown that gaining a better understanding of the synodal dimension in theology and in the Catholic Church’s activity is an important contribution the Church can make in ecumenical dialogue, also for a more adequate understanding of the close bond between synodality and primacy.

The ecumenical dimension of synodality was also highlighted at the General Assembly of the Synod of Bishops. Pope Francis reminded participants more than once of the interdependence between synodality and the ecumenical journey, affirming that the synodal process undertaken by the Catholic Church must be ecumenical, just as the ecumenical journey is synodal. For this reason, in the Catholic Church, synodality is presented and discussed in an ecumenical light.

The Authority of Church
and State

However, there is a fundamental difference that must not be overlooked between the Council of Nicaea and today’s efforts to revitalize synodality. At first glance it may seem insignificant, but its relevance becomes apparent if seen from an ecumenical perspective. We are referring to the historical fact that the Council of Nicaea was convened by a state authority, namely, by Emperor Constantine. Constantine perceived the dispute about the Christological confession as a great threat to his project to consolidate the empire on the basis of the unity of the Christian faith. Given the possibility of an imminent division in the Church, he saw a predominantly political problem; and yet, he was foresighted enough to realize that the Church’s unity had to be ensured not in a political way, but in an ecclesiastical-theological one. To reconcile the communities in conflict at the time, he convened the First Ecumenical Council in the city of Nicaea in Asia Minor, near the imperial residence of Nicomedia.

One of the unfortunate consequences of this approach is the fact that after Constantine, the emperors, in particular his son Constance, adopted a decisive policy to distance themselves from the creed of the Council of Nicaea, and they again promoted Arius’ heresy. That means that the Council of Nicaea’s decision did not put an end to the compatibility between the profession of faith in the divinity of Jesus Christ and the monotheistic belief of the fourth century, but rather, it rekindled the controversy surrounding the nature of Jesus Christ as belonging to God or to creation. These developments impelled Basil, the well-known bishop of Caesarea, to compare the situation following the Council of Nicaea to a nocturnal naval battle in which everyone fights against everyone, arriving at the conclusion that the conciliar controversies would result in terrible disorder and confusion and “endless gossip” in the Church.

From an ecumenical perspective, it is important to note that, due to this historical context, the Western and Eastern Churches saw the emergence of different ideas about the relationship between Church and State. What the Western Church learned from a long and complicated history was that the right way to shape her relationship with the State was to keep the two separate while remaining a partnership. In the Eastern Church, on the other hand, the model that spread widely was that of a close relationship between the state government and the ecclesiastical hierarchy, usually described as a “symphony between State and Church”. This is especially evident in the Orthodox concepts of autocephaly and canonical territory.

The various traditions used to set up the Church-State relationship have often been the backdrop of conflicts between the Western and the Eastern Church throughout history, and they have also had a significant impact on ecumenical relations. However, said traditions are among the least-discussed topics in ecumenical conversations. This is why it will be crucial to include them among the first points in the order of business of the ecumenical day, especially with the great anniversary of the Council of Nicaea taking place in 2025.

The 1,700th anniversary of the Council of Nicaea is thus not only a fruitful occasion for the ecumenical communion to renew its profession of faith in Jesus Christ, the Son, consubstantial with the Father, but also an important challenge, namely, that of clearly dealing with and discussing past problems that remain unresolved and which have not been sufficiently addressed in the ecumenical debates held until now. If the opportunity and the challenge are welcomed in the same way, the 1,700th anniversary of the Council of Nicaea will prove to be a great turning point for the future of ecumenism.