In 2025, Christians worldwide commemorate the 1700th anniversary of the First Council of Nicaea, a defining moment in Church history that continues to shape Christian doctrine and unity. Convened in 325 AD by Emperor Constantine, the Council was a response to growing theological divisions, particularly the teachings of Arius, a priest from Alexandria. Arius claimed that Jesus Christ was not eternal but a created being, subordinate to God the Father—a view known as Arianism.
To counter this, the bishops at Nicaea formulated a creed affirming that Jesus is “begotten, not made, being of one substance (homoousios) with the Father.” This declaration was crucial in asserting Christ’s full divinity and co-eternity with the Father. Though the original creed briefly mentioned the Holy Spirit, further theological disputes led to its expansion at the First Council of Constantinople in 381 AD. This revised version, known as the Niceno-Constantinopolitan Creed, affirmed the divinity of the Holy Spirit and added statements about the Church, baptism, and resurrection – forming a more complete expression of Christian orthodoxy.
An icon representing the First Ecumenical Council of Nikea 325 A.D., with the condemned Arius in the bottom of the icon, found at the Mégalo Metéoron Monastery in Greece. Image: Wikimedia Commons
To commemorate this significant anniversary, there will be a special Mass at St Patrick’s Cathedral, Parramatta, on Sunday 24 August 2025 at 11am which will be celebrated by Bishop Vincent Long OFM Conv, Bishop of Parramatta.
As part of the liturgy, the renowned St Patrick’s Cathedral Choir will perform the Credo from Palestrina’s Missa Papae Marcelli. This musical reflection invites worshippers to contemplate the eternal truths of the creed through the transcendent beauty of Renaissance polyphony. The performance also marks the 500th anniversary of the birth of Palestrina, whose sacred music has long been revered for its clarity and spiritual depth.
Global celebrations and renewed dialogue
Globally, churches and ecumenical bodies are marking the anniversary with theological conferences, liturgical celebrations, and pilgrimages. The World Council of Churches, the Greek Orthodox Archdiocese of America, and the Vatican’s Dicastery for Promoting Christian Unity are leading initiatives that highlight the Council’s legacy and its relevance for modern Christian witness.
Importantly, the anniversary is also fostering renewed dialogue between the Orthodox Churches and the Roman Catholic Church. Both traditions regard the Council of Nicaea as a shared foundation of faith, predating later schisms. The Nicene Creed, still recited in both Eastern and Western liturgies, serves as a powerful symbol of unity. Recent conferences and joint statements have emphasised the potential of this anniversary to deepen mutual understanding and move toward greater communion.
As the Church reflects on 1700 years since Nicaea, the anniversary serves as a call to unity, truth, and shared witness. Whether through solemn liturgies, sacred music, or ecumenical dialogue, the spirit of Nicaea continues to inspire Christians to profess their faith with clarity and seek reconciliation across traditions.
All are invited to attend the Mass on 24 August 2025. The Mass will also be livestreamed here: https://www.youtube.com/watch?v=gVVUIYt_uvE
This Mass is an important example of a Church renewed in Spirit and Prayer, embedded in the Diocese of Parramatta’s Pastoral Plan. This focus on prayer and dialogue fosters greater participation, worship and faith formation as the Diocese strives to prioritise Prayer and Mission.
Bernard Kirkpatrick is the Director of Music at St Patrick’s Cathedral, Parramatta.
