ISTANBUL (CNS) -- Pope Leo XIV, like his two immediate predecessors, visited the so-called Blue Mosque in Turkey's capital; he spent about 20 minutes inside but did not appear to pause for prayer as Pope Benedict XVI and Pope Francis had done.

Instead, he listened to Askin Musa Tunca, the mosque's muezzin who calls people to prayer five times a day, explain the building, its construction and how Muslims pray. And the pope asked questions. 

Tunca told reporters afterward that the mosque is "the house of Allah -- it's not my house; it's not your house," and so he told Pope Leo he could pray if he wanted. "'That's OK,' he said, he wanted to see the mosque."

Reporters pressed Tunca, asking again if the pope prayed. "Maybe to himself, I don't know," he responded.

The Vatican press office said afterward that Pope Leo visited the mosque "in a spirit of reflection and attentive listening, with deep respect for the place and for the faith of those who gather there in prayer."

As is customary, Pope Leo removed his shoes in the courtyard before entering the mosque in white socks. 

Formally called the Sultan Ahmed Mosque, the Muslim house of prayer was complete in 1617 and is known as the Blue Mosque because of the more than 21,000 blue tiles that decorate its walls, arches and domes. The tiles come from Iznik, site of the ancient Nicaea, which Pope Leo had visited the day before.

Leaving the mosque, Pope Leo noted to Tunca that they were going through a doorway with a sign that said, "No exit." The muezzin replied that the sign was for tourists but, if the pope preferred, "you do not have to go out. You can stay here."

Pope Benedict XVI had visited the Blue Mosque in 2006, and Pope Francis toured it in 2015. Both had paused for a moment of silence facing the mihrab, which indicates the direction of the Islamic holy city of Mecca. St. John Paul II was the first pontiff to visit a mosque when he went to the Umayyad mosque in Damascus, Syria, in 2001. 

In late October Pope Leo had led Vatican celebrations of the 60th anniversary of Nostra Aetate, the Second Vatican Council's document on relations with other world religions. The bishops at Vatican II said Catholics have esteem for their Muslim brothers and sisters, who "adore the one God, living and subsisting in himself; merciful and all-powerful, the Creator of heaven and earth," and "they take pains to submit wholeheartedly to even his inscrutable decrees."
 

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Istanbul, Turkey, Nov 29, 2025 / 03:10 am (CNA).

Pope Leo XIV started his third day in Turkey on Saturday with a visit to the Sultan Ahmed Mosque in Istanbul. The visit was a gesture of respect toward the Islamic world, fraternity with Muslims, and continuity in building bridges of interreligious dialogue, though the pope declined an invitation to pray in the Muslim house of worship.

The so-called “Blue Mosque” stands as one of the most important Islamic buildings in Istanbul. Its beauty, its scale, and its history continue to attract visitors from all over the world. It also holds a unique place in the relationship between Christianity and Islam, as several popes have passed through its doors in silence and respect.

Benedict XVI visited the mosque in 2006 during his visit to the country. The visit came less than three months after an address he made in Regensburg, Germany, in which he quoted a medieval emperor’s description of Islam as “evil and inhuman” and “spread by the sword,” provoking a fierce reaction in the Muslim world. The Vatican’s spokesman at that time, Father Federico Lombardi, said that Benedict paused for meditation inside the mosque. Pope Francis entered the mosque in 2014 and stood in what the Vatican described as a “moment of silent adoration” of God inside the Muslim place of worship.

After Leo’s visit on Saturday, the Holy See Press Office said in a statement that “the pope experienced the visit to the mosque in silence, in a spirit of reflection and attentive listening, with deep respect for the place and for the faith of those who gather there in prayer.”

One of the pope’s hosts for the visit, muezzin Aşgın Musa Tunca, told reporters afterward that he had told the pope he was welcome “to worship here” but that Leo had replied: “No, I am just going to look around.”

A notable omission from Leo’s itinerary, and a point of tension in Catholic-Islamic relations, is Hagia Sophia, the Byzantine church-turned-mosque that the Turkish government designated a museum open to all faiths in the 20th century. Popes Paul VI, John Paul II, Benedict XVI, and Francis all visited the monument on previous papal visits to Turkey. Francis said he was “deeply pained” when the government turned it back into a mosque in 2020.

Asked on Thursday why Leo would not be visiting Hagia Sophia, Bruni said: “It simply was not put on the program.”

The “Blue Mosque,” which Leo visited on Saturday, was built between 1609 and 1617 by Sultan Ahmed I. It occupies part of the site where the Grand Palace of Constantinople once stood. The goal was to make it the most important place of worship in the Ottoman Empire.

The construction process was carefully organized. The name “Blue Mosque” comes from approximately 21,000 turquoise ceramic tiles placed along the walls and the main dome. Walls, arches, and columns carry the famous Iznik tiles in tones from blue to green. Light entering through 260 small windows also gives the prayer hall a remarkable atmosphere.

The Sultan Ahmed Mosque is the only mosque with six minarets. Most mosques have four. Only one of the Ka’ba in Mecca, Saudi Arabia, exceeds it, with seven.

Correction: An earlier version of this story referred to Father Federico Lombardi as Father Pietro Lombardi. The story has been updated with the correct name. (Published Nov. 29, 2025)

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On the morning of the third day of his Apostolic Journey to Türkiye, Pope Leo XIV visits the Sultan Ahmed Mosque, also known as the “Blue Mosque.”

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ACI MENA, Nov 28, 2025 / 10:05 am (CNA).

Pope Leo XIV began the second day of his apostolic journey to Turkey at the Cathedral of the Holy Spirit in Istanbul, a vital spiritual home for a diverse Catholic community largely made up of immigrants from across the world. The cathedral — long a customary stop for pontiffs visiting Turkey — welcomed the Holy Father with profound emotion and vibrant hope.

At the entrance, Pope Leo was received by Father Nicola Masedu, a Sardinian priest who has served in Turkey for more than 15 years and lived a life marked by mission across the Middle East. He first moved to Lebanon at the age of 17, later to Iran — where he was briefly arrested — then to the Holy Land, and finally to Istanbul. 

In an interview with ACI MENA, CNA’s Arabic-language news partner, Masedu recalled that the first pope he met was Pope Paul VI, whom he greeted at the Beirut airport during a brief stopover on the pontiff’s way to India. He later met St. John Paul II in Castel Gandolfo after being forced to leave Iran and Pope Benedict XVI in Bethlehem in 2008.

Masedu also welcomed Pope Leo holding the same crucifix he once presented to Pope Francis. He explained that the crucifix originally belonged to the Sisters of Charity at the Austrian Hospital, who gifted it to the parish when they were clearing out some of their rooms. “That crucifix has a history of prayer and protection,” he said, adding a personal memory: “It was a point of reference for Kamila, our little parrot, who — whenever she was frightened — would fly into my office and take refuge near it.”

Masedu also shared with ACI MENA the symbolic gift the community prepared for Pope Leo: a silver chalice crafted by an Armenian artist, engraved with the six apostles who brought Christianity to this land. 

From this deeply symbolic offering, the priest reflected on the ancient Christian roots of Turkey, reflecting on the fact that this land once stood at the heart of the early Church. He emphasized the spirit of ecumenical unity that binds the different churches together in their effort, as he said, “to remain close to one another.”

He spoke candidly about the challenges facing his community, especially immigrants who struggle with financial hardship, residency permits, and at times, discrimination. Still, the parish works tirelessly to accompany them both spiritually and materially, offering education, social support, and medical assistance when necessary, as well as retreats and psychological accompaniment.

Reflecting on the difference between Christian life in Lebanon and Turkey, Masedu noted that in Lebanon he felt “at home,” surrounded by visible Christian symbols, whereas in Turkey churches remain largely hidden from view, with St. Anthony’s Basilica on İstiklal Street being a notable exception. He concluded by expressing his hope that Pope Leo’s visit will strengthen the Christian community, encouraging them to persevere and continue working for peace.

Exiled for his faith

Among the parishioners present this morning was Suhail, a 36-year-old Iranian who arrived in Turkey seven years ago after converting to Christianity. Forced to leave Iran because of his faith, he now works closely with a community of Catholic Iranians who have also sought refuge in Turkey.

Suhail confirmed that practicing Christianity in Turkey is “immeasurably safer” than in Iran, where he was previously arrested. Yet, mindful of the danger facing Christians still in his home country, he chose not to share details about the persecution there so as not to put anyone at further risk.

Instead, he spoke with gratitude about the religious freedom he has found in Istanbul and about the dignity of being able to live and worship openly: “I can pray, I can attend Mass, and I can grow in my faith. For this, I am thankful,” he said.

Suhail has been helping in the cathedral for months in preparation for the papal visit, and he described the opportunity to welcome Pope Leo as “a blessing beyond words.”

An African voice

Also sharing his joy was Philip Tata, originally from Cameroon and now serving as president of the youth group at the Cathedral of the Holy Spirit. 

Having lived in Gabon before moving to Turkey four years ago, Tata spoke about the remarkable diversity that shapes the parish community. He explained that Mass is celebrated in English, Turkish, and French, reflecting the presence of a large African community, many of whom come from French-speaking countries.

Tata recalled how Pope Francis previously met with refugees in this very church, and he believes Pope Leo is continuing on the same pastoral path, placing special emphasis on migrants, displaced people, and those living on the margins. Pope Leo explicitly mentioned refugees and immigrants in his message this morning, a moment that deeply moved the congregation.

Reflecting on the Catholic youth in Turkey, he said that many young people hope to leave, not because of religious persecution but because of the limited economic opportunities and scarcity of jobs, which push them to search for a more stable future elsewhere. Still, he expressed hope that the papal visit might inspire renewed support and encouragement for the younger generation.

Lebanese voices singing for the pope in Istanbul

Among the faithful gathered in the cathedral were also Lebanese Catholics who now live in Turkey and will not be in Lebanon when the pope visits their homeland on Sunday. Yet, providentially, they encountered him here, in what has become their second home, and even had the chance to sing for him as part of the choir.

Sleiman Saikali, who has lived in Turkey for 30 years, is traveling to İznik to sing for the pope during the historic commemoration of the Council of Nicaea. He shared his deep joy at welcoming Pope Leo in a place that symbolizes both his roots and his present life. He said he has been preparing for months, not only by training his voice but also spiritually through prayer.

He spoke passionately about the mission behind this papal journey, insisting that each country carries a distinct vocation. He recalled being present at the visits of Pope Benedict XVI and Pope Francis to Turkey. “Benedict was a man of extraordinary theological depth, and his visit with Patriarch Bartholomew was an unforgettable ecumenical moment. Francis was like a positive revolution — he returned the Church to the poor and the simple, to justice and humility.”

Looking to Pope Leo, he expressed profound hope: “In him I see a blend of Benedict, Francis, and John Paul II. Since John Paul, God has given the Church popes who walk with the signs of the times, and this is God’s work, not ours.” For Christians in Turkey, he said, papal visits are vital. “As a very small minority, we carry the beauty of keeping the faith, but the danger of isolation is real. We must not isolate ourselves.”

Also part of the choir is Lili El-Helou, a Lebanese student who came to Turkey two years ago. She never imagined she would one day sing before the pope, yet today she stood among those performing at the Cathedral of the Holy Spirit. She will also chant the Kyrie Eleison in the Maronite melody on Saturday at the arena. 

El-Helou described how her spiritual life has deepened since moving to Istanbul, portraying the parish as active, united, and vibrant, despite the small number of Catholics. She said she feels at peace living her faith in Istanbul. However, she noted that the situation can be “more difficult” in other cities such as İzmir, where religious sisters sometimes hesitate to appear in their habits due not to legal restrictions but to reactions, comments, and intrusive stares.

A Chaldean presence 

The atmosphere in the cathedral Friday was lifted by a multilingual choir, whose voices filled the church with hymns in different languages including Syriac, a reminder of the ancient Christian heritage rooted in this land. 

Among them was Sister Sandra, a Chaldean nun from the Nuns of the Sacred Heart, who described the opportunity to sing in Syriac — the language spoken by Jesus and preserved by the Eastern Churches — as “a profound grace and a moment of great beauty.” 

She asked all believers to pray for Turkey, the pope, and the Christian community in Turkey, expressing hope that the visit will strengthen unity and peace.

Washington, D.C. Newsroom, Nov 28, 2025 / 10:00 am (CNA).

In the summer of A.D. 325, more than 300 bishops gathered in Nicaea — located in modern-day northern Turkey — to promulgate a common Christian creed, settle Christological disputes that arose from the Arian heresy, and promote unity in the Church.

The first ecumenical council, known as the Council of Nicaea, is still accepted as authoritative by the Catholic Church, the Eastern Orthodox Church, and many Protestant denominations. The common beliefs still offer a strong element of unity in an otherwise fractured Christianity 1,700 years later.

During the council, the bishops established the initial formulation of the Nicene Creed, which is the profession of faith still recited at the Catholic Mass, Orthodox liturgies, and some Protestant services. It also rejected heretical Arian claims that Christ was a created being who lacked an eternal divine nature and rather confirmed that the Son is eternally begotten of the Father.

The council was called by Emperor Constantine — a convert to Christianity — less than 15 years after the empire halted the persecution of Christians and granted them the freedom to worship. It came just 20 years after the reign of Emperor Diocletian, who brutally persecuted Christians for their rejection of paganism.

“That council represents a fundamental stage in the development of the creed shared by all the Churches and ecclesial communities,” Pope Leo XIV said in May, acknowledging the 1,700th anniversary.

“While we are on the path towards the reestablishment of full communion among all Christians, we recognize that this unity can only be unity in faith,” the pontiff said.

The Arian heresy

The primary purpose of the council was to settle a major question about Christ’s divine nature and address Arianism, which was a heresy promoted by the priest Arius asserting that Jesus Christ was a created being and not eternal.

“Arius began to preach something that was scandalous to many Christian believers and [which] seemed incompatible to the Christian faith as witnessed to in Scripture and transmitted through the tradition of the Church,” Dominican Father Dominic Legge, the director of the Thomistic Institute and a professor of theology, told CNA.

Arius wrote in “Thalia” that he believed the Father “made the Son” and “produced him as a son for himself by begetting him.” He wrote that “the Son was not always [in existence], for he was not [in existence] before his generation.” He asserted that Christ was not eternal but “came into existence by the Father’s will.” Arius contested that Christ “is not true God” but was rather “made God by participation.”

Legge said that Arius understood that “there’s an infinite gap between God and creatures,” but where he was mistaken was that “he thought that the Son was on the ‘creature’ side of that gap” and “not equal in divinity to God.”

“Therefore, he considered him to be the highest creature,” Legge added. “The first creature, but nonetheless a creature.”

Legge said that at Nicaea there was “a consensus of bishops with very different approaches to the mystery of God and they could see that Arius had to be wrong and so they condemned him and they affirmed that the Son is ‘God from God, true God from true God.’”

The language adopted at Nicaea expressly contradicted Arius, affirming Christ is “true God from true God, begotten not made, of one substance with the Father.” It condemned Arius’ view as heresy. The vote was nearly unanimous with more than 300 bishops voting in favor of this text and only two siding with Arius.

St. Athanasius, one of the most outspoken opponents of Arianism at the council and in its aftermath, wrote in his “First Discourse Against the Arians” in the mid-fourth century that “the Scriptures declare the Son’s eternity.”

Athanasius notes, for example, the Gospel of St. John states that “in the beginning was the Word, and the Word was with God, and the Word was God.” He also cites Chapter 8 of the same Gospel in which Christ declares “before Abraham was, I am,” invoking the divine name used by God to indicate his eternity when appearing to Moses as the burning bush.

“The Lord himself says, ‘I am the Truth,’ not ‘I became the Truth,’ but always, ‘I am — I am the Shepherd — I am the Light‘ — and again, ‘Call me not, Lord and Master? And you call me well, for so I am,‘” Athanasius wrote. “Who, hearing such language from God, and the Wisdom, and Word of the Father, speaking of himself, will any longer hesitate about the truth, and not immediately believe that in the phrase ‘I am,‘ is signified that the Son is eternal and without beginning?”

Legge noted that Athanasius also warned that Arius’ position “threatened the central truth of Christianity that God became man for our salvation.”

Unifying the Church in the fourth century

Prior to the Council of Nicaea, bishops in the Church held many synods and councils to settle disputes that arose within Christianity.

This includes the Council of Jerusalem, which was an apostolic council detailed in Acts 15, and many local councils that did not represent the entire Church. Regional councils “have a kind of binding authority — but they’re not global,” according to Thomas Clemmons, a professor of Church history at The Catholic University of America.

When the Roman Empire halted its Christian persecution and Emperor Constantine converted to the faith, this allowed “the opportunity to have a more broad, ecumenical council,” Clemmons told CNA. Constantine embraced Christianity more than a decade before the council, though he was not actually baptized until moments before his death in A.D. 337.

Constantine saw a need for “a certain sense of unity,” he said, at a time with theological disputes, debates about the date of Easter, conflicts about episcopal jurisdictions, and canon law questions.

“His role was to unify and to have [those] other issues worked out,” Clemmons said.

The pursuit of unity helped produce the Nicene Creed, which Clemmons said “helps to clarify what more familiar scriptural language doesn’t.”

Neither the council nor the creed was universally adopted immediately. Clemmons noted that it was more quickly adopted in the East but took longer in the West. There were several attempts to overturn the council, but Clemmons said “it’s later tradition that will affirm it.”

“I don’t know if the significance of it was understood [at the time],” he said.

The dispute between Arians and defenders of Nicaea were tense for the next half century, with some emperors backing the creed and others backing Arianism. Ultimately, Clemmons said, the creed “convinces people over many decades but without the imperial enforcement you would expect.”

It was not until 380 when Emperor Theodosius declared that Nicene Christianity was the official religion of the Roman Empire. One year later, at the First Council of Constantinople, the Church reaffirmed the Council of Nicaea and updated the Nicene Creed by adding text about the Holy Spirit and the Church.

Common misconceptions

There are some prominent misconceptions about the Council of Nicaea that are prevalent in modern society.

Clemmons said the assertion that the Council of Nicaea established the biblical canon “is probably the most obvious” misconception. This subject was not debated at Nicaea and the council did not promulgate any teachings on this matter.

Another misconception, he noted, is the notion that the council established the Church and the papacy. Episcopal offices, including that of the pope (the bishop of Rome), were already in place and operating long before Nicaea, although the council did resolve some jurisdictional disputes.

Other misconceptions, according to Clemmons, is an asserted “novelty” of the process and the teachings. He noted that bishops often gathered in local councils and that the teachings defined at Nicaea were simply “the confirmation of the faith of the early Church.”

This story was first published on June 5, 2025, and has been updated.