Pope Leo XIV’s Nicaea moment and the missing Filioque

Pope Leo XIV joined Orthodox, Oriental Orthodox and Protestant leaders in Turkey this week to commemorate the 1,700th anniversary of the First Ecumenical Council, marking one of the most symbolically charged ecumenical gatherings of his pontificate.

The prayer service, held in modern-day Iznik, which used to be Nicea, brought together twenty-seven heads of Churches and Christian communities in a setting uniquely associated with the earliest definitions of Christian doctrine.

During the liturgy, the Pope and the assembled leaders recited the Niceno-Constantinopolitan Creed in English, using the original Greek form without the Filioque clause.

The joint recitation rendered the line concerning the Holy Spirit as “who proceeds from the Father”, omitting the Latin tradition’s “and the Son”.

In his prepared address, Pope Leo XIV thanked Ecumenical Patriarch Bartholomew I for what he described as the Patriarch’s “great wisdom and foresight” in calling Christian leaders to mark the anniversary together.

Reflecting on the Council of Nicaea, the Pope said the gathering “invites all Christians to ask ourselves who Jesus Christ is for us personally”, warning that reducing Christ to “a charismatic leader or superman” leads only to confusion.

The Pope highlighted the council’s defence of Christ’s full divinity against Arianism and noted that its confession of the Son as “consubstantial with the Father” remains a point of unity for Christians worldwide.

He appealed to the leaders present to continue along “the paths of fraternal encounter, dialogue, and cooperation”, especially in a global climate marked by violence and instability.

“We must strongly reject the use of religion for justifying war, violence, or any form of fundamentalism or fanaticism,” he said.

The event followed closely on the release of the Pope’s new apostolic letter, In Unitate Fidei, published earlier in the week. Near its conclusion, the letter quotes in its footnotes that the Creed uses the Eastern form without the Filioque. A footnote explains that the phrase “is not found in the text of Constantinople” and is “a subject of Orthodox-Catholic dialogue”.

As the service concluded, the leaders prayed together for reconciliation and the strengthening of Christian unity, with Pope Leo XIV expressing hope that the Nicaea commemoration would bear “abundant fruits of peace”.

For some Catholics, the Pope praying the Niceno-Constantinopolitan Creed in Nicaea without the Filioque may be a head scratcher in terms of how far can genuine ecumenism can go before it becomes something else.

This matters, because the Church is not merely a diplomatic actor among others. She teaches the truth about God and the human person, and her unity is rooted not in sentiment but in doctrine.

When the Pope and the Ecumenical Patriarch recite together “the Holy Spirit … who proceeds from the Father”, while omitting the Latin tradition’s confession “and the Son”, the gesture is immediately read not merely as hospitality but as a theological signal.

For a Church increasingly pressured to dilute doctrine for consensus, the stakes are unmistakably high.

What is at stake is that the prayer at Iznik cannot be understood only as a theological dispute or an ecumenism courtesy. It reveals a deeper pattern in the Church’s post-conciliar instinct, an instinct to heal division through symbolic conciliation, even when those symbols touch the very formulations defended by a millennium of saints, councils and popes.

At its core, the event demonstrated how the Church is living through a renewed struggle over the meaning of unity: unity in truth versus unity by accommodation.

The Pope’s decision to pray the Creed in it the non-Filioque form, together with the content of his apostolic letter In Unitate Fidei, has brought that struggle into sudden clarity.

Beyond the prayer event, if one looks at a thousand years of Church history, the West has confessed the Spirit’s procession as “from the Father and the Son”.

This is not something minor, rather a pillar of Western Trinitarian theology, defended by Saint Augustine, Ambrose, Leo the Great, the councils of Toledo and the entire medieval tradition.

Pope Leo I taught in 447 that those who deny that the Spirit proceeds from both are guilty of an “impious” error. The councils of Toledo inserted the clause to combat Arianism. And when the  entered the Roman liturgy in 1014, it did so as a crystallisation of Western faith, not as an arbitrary embellishment.

So when the Pope prays the Creed publicly beside Patriarch Bartholomew without the Filioque phrase, Catholics naturally ask, what exactly is being signalled?

Pope Leo XIV himself insisted in Nicaea that the Council “invites all Christians … to ask ourselves who Jesus Christ is for us personally”, and he recalled its confession of Christ as “consubstantial with the Father”.

These are strong and mighty words – but the symbolism of using the Eastern Orthodox Credo while standing with leaders of communities who reject the Filioque was likely to provoke unease in some quarters.  

The use of it here is obviously not a change of dogma. The Pope has not repudiated the councils of Florence, Lyons, or the consistent Latin Magisterium. Catholics need not fear that doctrine has changed.

But we must recognise that symbolic gestures shape the Church’s future debates, and such gestures by a Pope represent an emphasis – and emphasis in the Church always forms expectation.

The omission of the Filioque in Nicaea and in In Unitate Fidei reveals a Church trying to balance truth and unity at a moment when compromise is easy and clarity is costly.

The Church deserves unity. But she deserves it rooted in the fullness of truth. Every generation must decide whether it will preserve what has been handed down or quietly set it aside in the hope that goodwill alone will heal a millennium of division.

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Photo: Pope Leo XIV takes part in a prayer service near the excavations of the ancient Basilica of Saint Neophyto, Iznik, Turkey, 28 November 2025. The service held in Iznik, the site of ancient Nicaea, commemorates the 1,700th anniversary of the Council of Nicaea, which established key Christian doctrines. Pope Leo XIV is making his first foreign trip on a six-day visit to Turkey and Lebanon. During his trip, the Pope is scheduled to meet with faithful from local Catholic communities, as well as political and religious leaders. (Photo by Chris McGrath/Getty Images.)