From 5 to 7 June 2025, the International Ecumenical Conference “Nicaea and the Church of the Third Millennium” took place at Pontifical University of St. Thomas Aquinas, organized by the International Orthodox Theological Association in cooperation with the University, which is one of the institutional members of the Societas Oecumenica.
More than 200 theologians and ecclesiastical experts from the most renowned academic and ecumenical organizations took part in this historic meeting on the 1700th anniversary of the Council of Nicaea in 325. Present were academics, but also representatives of churches throughout the Christian spectrum: from the ancient Eastern Churches, through the Orthodox Churches, the Roman Catholic Church and churches that share the traditions of the Reformation.
The plenary programme of the conference was divided into three parts, dealing with the themes of “The Nicene Creed”, “Nicea and Synodality” and “The Date of Easter”. In addition to the morning plenary sessions, there were also afternoon breakout sessions. One of these was sponsored by the Societas Oecumenica. On Friday, June 6, four members of the Societas reflected on the theme “Rediscovering Nicaea in the Churches Today”. The session, moderated by Societas Oecumenica President Simone Sinn, heard suggestions from Lutheran (Heta Hurskainen), Roman Catholic (Robert Svaton), Orthodox (Aleksei Volchov) and Baptist (Joshua Searle) perspectives. All speakers emphasized the ecumenical significance and challenges of the Council of Nicaea for the life of the churches today.
Other members of the Societas Oecumenica actively participated in the conference: Johannes Oeldemann moderated a session sponsored by the St. Irenaeus Joint Orthodox-Catholic Working Group, Dimitrios Keramidas presented an Orthodox commentary on the document “The Bishop of Rome“, Peter-Ben Smith gave a lecture on “Believing in the Church as a Resource for Ecumenical Rapprochement”, Jennifer Wasmuth presented a paper on the Nicene Creed in the context of Reformation confessional texts, and Natascha-Ingrid Tinteroff spoke on the significance of the Council of Nicaea for the praxis of synodality in the Anglican Communion.
On Saturday, 7 June, the conference participants were received in the Vatican’s Clementine Hall by Pope Leo XIV. He particularly appreciated the conference’s focus on the future of the life of the Churches: “The Council of Nicaea is not merely an event of the past but a compass that must continue to guide us towards the full visible unity of Christians”.
