Pope Leo XIV's bold project: a global unified Christianity

Pope Leo XIV has been in office for a year. His papacy looks, from a distance, like Francis: same instincts on poverty, migration, and the global south. The distance is misleading. Leo has spent his first year on a specific project, one that no pope has seriously attempted in decades: narrowing the fractures that split Christianity in 1054.

What he did

In June 2025, weeks after his election, Leo told Orthodox leaders the Catholic Church was open to a common Easter date [1]. The 1997 Aleppo Statement, an ecumenical proposal for a shared astronomical calculation, had gone nowhere for thirty years. Leo was signaling the Catholic side was ready to move.

In November, he traveled to Iznik, Turkey, for the 1,700th anniversary of the Council of Nicaea, and recited the Nicene Creed alongside Orthodox leaders in its original Greek form, without the filioque [2]. The same day, he and Patriarch Bartholomew I signed a Joint Declaration committing both churches to dialogue toward full communion and a shared Easter date [3].

In April 2026, Leo became the first pope in history to visit Algeria [4]. He stood before the qibla of the Great Mosque of Algiers. The trip was framed around Augustine, who was born in what is now Algeria, but Augustine was the frame. The actual point: the Catholic Church's roots in Africa predate its roots in Europe.

Why the filioque is not a small thing

The filioque (“and from the Son”) is the word Rome added to the Nicene Creed in the ninth century without convening an ecumenical council. The original creed, agreed at Nicaea in 325, stated the Holy Spirit proceeds from the Father alone. The Eastern church's refusal to accept Rome's addition is the doctrinal fault line of the 1054 Great Schism. The last serious attempt at reconciliation was the Council of Florence in 1439, which produced an agreement that collapsed within decades.

Leo's decision to omit the filioque in a joint liturgy, on the anniversary of the council that predates the dispute, is an acknowledgment that the Eastern position has always had standing [5]. His formal letter on the Creed, issued before the trip, framed the Nicaea anniversary as a moment to recommit to the unity its authors intended [6]. The Iznik trip is not a diplomatic gesture. It is a position.

The Easter date is a simpler problem, which is part of why Leo moved on it first. Two traditions marking the resurrection on different dates because of competing calendar systems is a scheduling disagreement, not a doctrinal one. The Joint Declaration converts the thirty-year-old Aleppo proposal into a shared commitment at the highest level of both churches.

What it adds up to

Leo is making the same argument three ways. Algeria says the church is not European: it predates European Christianity, and the majority of its 1.4 billion members live outside Europe and North America. The filioque gesture says Rome has not always acted with the authority it claims, and acknowledging that is not a concession. The Easter push says the practical obstacles to unity are solvable, and not solving them is a choice.

Papal authority is the structural problem none of this resolves. The Orthodox churches have no equivalent to the papacy, and full communion requires working out what shared governance would actually look like. What Leo has established in his first year is that the Catholic Church is serious about the question, and that the church it claims to represent is more universal than it has allowed itself to become.

Sources

[1] The Catholic Thing – Pope to Orthodox leaders: We're open to a universal Easter date

[2] Aleteia – Why did Leo leave words out of the Creed in Turkey?

[3] Vatican – Joint Declaration of Leo XIV and Bartholomew I

[4] National Catholic Reporter – Pope Leo arrives in Algeria preaching harmony, visits mosque

[5] Catholic Herald – Pope Leo XIV's Nicaea moment and the missing Filioque

[6] USCCB – Pope issues apostolic letter on the Creed, marking anniversary of Nicaea