In this extraordinary year, 2025, the 1,700th anniversary of the Council of Nicaea, we remember not only a moment of theological resolution, but a moment that forged the very identity of the Christian Church in her public confession of faith.

From a Catholic perspective, the Council of Nicaea in 325 CE is nothing less than a watershed in salvation history. Convened by Emperor Constantine and guided by the Holy Spirit, it drew over 300 bishops — some bearing the scars of persecution — to discern, define, and defend the apostolic faith amidst the storm of the Arian controversy. It protects the heart of the Gospel — the truth of who Jesus Christ is.

Arius, from Alexandria, had taught that the Son of God was not eternal but created — that there was a time when He was not. This teaching, subtle yet subversive, threatened to fracture the Church’s proclamation of Christ’s divinity. The bishops, in a remarkable act of synodal discernment, responded not with innovation but with fidelity: affirming that Jesus Christ is “God from God, Light from Light, true God from true God, begotten, not made, consubstantial with the Father.”

This phrase — consubstantialem Patri in Latin, homoousios tō Patri in Greek — is not theological embroidery; it is the keystone of our Christian faith. It safeguards the mystery of the Incarnation, the very heart of our redemption. If Christ is not truly God, then God has not truly entered into human history. If Christ is not one in being with the Father, then the Cross cannot save us.

As Catholics, we recite this Creed every Sunday at Holy Mass. It is not a relic of a bygone council, but a living act of faith, uttered in the communion of saints. It is the breath of the Church’s belief — uniting bishop and layperson, East and West, age to age. It connects us across time and place — from the fourth century to today, from small village chapels to the grandeur of St Peter’s Basilica. It reminds us that faith is not just personal  but shared.

In the words of Pope Benedict XVI:

“The Creed is not a collection of propositions; it is a sacramental act, a profession made in the Holy Spirit, in the Church.”

The Council of Nicaea, then, is not merely a historical event to be studied, but a spring of unity to be rediscovered. The Catholic Church sees in this an example of how truth is discerned: not in isolation, but in communion in dialogue, and in fidelity to the apostolic faith.

Pope John Paul II, writing in Ut Unum Sint, emphasised this very point:

“The ecumenical councils are milestones on the path of unity. They express the Church’s constant effort to remain faithful to the truth handed down.”

And today, we might see in Nicaea not only the triumph of doctrine, but the possibility of deeper communion. We know that differences remain among Churches. And yet here, in this ancient profession of faith, we find common ground — not because we all agree on every aspect, but because we all look to Christ, true God and true man, crucified and risen, as the centre of our hope.

Though divided by history, our Churches still share this Creed. We may differ in structure, in language, in sacramental life — but when we proclaim “I believe in one Lord, Jesus Christ,” we proclaim it together.

This anniversary invites us to ask: what does it mean, after seventeen centuries, to be a people of one Creed? Can we dare to hope that what united the Church at Nicaea might one day unite us visibly again?

Pope Francis, addressing ecumenical leaders in Geneva, put it plainly:

“When we say the Creed together, we are already united. Let us not wait for full agreement before we walk side by side.”

Let me conclude, then, not with a summary, but with a call to action.

Seventeen centuries ago, the Church came together in a time of confusion and disagreement. They didn’t wait for perfect answers, but they trusted the Holy Spirit, they gathered in faith, and they gave us a Creed that still carries the weight of our deepest convictions.

If the Church at Nicaea had waited for perfect clarity, it would have splintered. If it had sacrificed truth for peace, it would have betrayed the Gospel. Instead, it gathered — bruised, diverse, but faithful — and gave us the Creed that still unites our lips today.

So let us honour Nicaea not with nostalgia, but with courage. Let us be, in this 1,700th year, bold enough to profess one faith, patient enough to seek one heart, and humble enough to pray — as Christ did on the eve of His Passion — “that they may all be one.”

My question is:

What challenges or opportunities do we face in helping the next generation of Christians appreciate the significance of the Creed — not just as history, but as living faith?

Elliot Vanstone
Senior Mission Adviser, Mission Directorate

_{Image: © The Second Council of Nicaea (Church of St. Thomas – Goudi), George E. Koronaois, Wikimedia. CC BY-SA 4.0.}

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