Pope Francis begins mending the schism with OrthodoxChristians

Pope seeks reconciliation with Orthodox Christians - CNN.com

Istanbul (CNN) -- Christianity is a religion frayed over the centuries into many denominations. OnSunday, Pope Francis and the head of a major one vowed to heal one of the church's oldest splits.

The Great Schism of 1054 separated the Catholic and Eastern Orthodox churches. Both professsimilar doctrine and worship in similar ways, but a millennium ago, Eastern Orthodoxy rejected theultimate authority of the Pope.

Francis and Patriarch Bartholomew I -- the spiritual leader of some 300 million Orthodox Christiansworldwide -- signed a declaration on Sunday committing to unity between the two churches.

Together, they celebrated a divine liturgy at the Patriarchal Church of St. George in Istanbul onFrancis' last day in the predominantly Muslim nation -- his first trip there.

Somber intonations and hymns reverberated through the church as the two spiritual leaders prayedand offered reflections and Francis tried to allay worries.

Unity, not submission

PopeFrancis and Istanbul's Grand Mufti Rahmi Yaran visit the Sultan Ahmet Mosque, popularly known asthe Blue Mosque, in Istanbul on Saturday, November 29. The Pope is on a three-day visit to thepredominantly Muslim country.

PopeFrancis visits the Hagia Sophia Museum in Istanbul on November 29.

PopeFrancis kisses the altar as he arrives to celebrate a Mass inside the Holy Spirit Cathedral in Istanbulon November 29.

PopeFrancis releases a dove at Istanbul's Holy Spirit Cathedral on November 29.

PopeFrancis arrives to attend an ecumenical prayer with Ecumenical Patriarch Bartholomew I at thePatriarchal Church of St. George in Istanbul on November 29.

PopeFrancis is welcomed by Ecumenical Patriarch Bartholomew I at the Istanbul Ataturk airport onNovember 29.

PopeFrancis leaves the Ataturk Mausoleum after laying a wreath at the grave site of Mustafa KemalAtaturk, founder of the Turkish republic, in Ankara, Turkey, on Friday, November 28.

ThePope pauses after laying a wreath at the Ataturk Mausoleum on November 28.

PopeFrancis follows Turkish soldiers carrying a wreath at the Ataturk Mausoleum on November 28.

ThePope, surrounded by security and officials, walks the grounds of the mausoleum November 28.

Turkish President Recep Tayyip Erdogan welcomes Pope Francis at the presidential palace inAnkara on November 28.

ThePope holds a press conference aboard his flight to Ankara on November 28.Pope Francis visitsTurkeyPope Francis visits TurkeyPope Francis visits TurkeyPope Francis visits TurkeyPope Francisvisits TurkeyPope Francis visits TurkeyPope Francis visits TurkeyPope Francis visits TurkeyPopeFrancis visits TurkeyPope Francis visits TurkeyPope Francis visits TurkeyPope Francis visitsTurkeyHIDE CAPTION

Photos: Pope Francis visits Turkey

Neither church will submit to nor assimilate the other, the Pope said in his homily, but they willwork "towards the restoration of full Communion."

"I want to assure each one of you here that, to reach the desired goal of full unity, the CatholicChurch does not intend to impose any conditions except that of the shared profession of faith,"Francis said.

He was at St. George's at the Patriarch's invitation, which he extended shortly after Francis'inauguration.

Sunday's celebrations marked the feast of St. Andrew, the founder of the Eastern Church. He wasalso the older brother of St. Peter, the founding father of the Catholic Church .

'Blood of martyrdom'

In his part of the call for unity, the Orthodox leader alluded to attacks by radical Islamists onChristians.

"We no longer have the luxury of isolated action," Bartholomew said. "The modern persecutors ofChristians do not ask which church their victims belong to. The unity that concerns us is regrettablyalready occurring in certain regions of the world through the blood of martyrdom."

Over the past decade, first al Qaeda and then ISIS have forced Christians to flee Iraq and Syria.

Far fewer Christians remain in areas under ISIS control. Some rely on their faith in God; others payterrorists a protection tax. Growing numbers, especially from Syria, have ended up in Turkey.Thenation is reeling from the influx of around 1.5 million Syrian refugees, the vast majority Muslim.

Religion is also splitting Turkey. Opponents fear its conservative government will weaken thesecular identity of the post-Ottoman Empire.

Instability rages at its border, with ISIS and its leader, Abu Bakr al-Baghdadi, announcing theirintention to take over large swaths of territory for their self-proclaimed Islamic State.

Fourth pope in Turkey

Francis is the fourth pope to travel to Turkey, following in the footsteps of Paul VI, John Paul II andBenedict XVI.

The Pope was also expected to meet with young people from the Salesian community from Turkey,the Middle East and Africa before heading to the airport later Sunday. Salesians, the second largestCatholic order, help orphans and at-risk children, according to their website.

On Friday, the first day of his visit, Francis called for religious tolerance and dialogue to counterextremism in the Middle East, as he met with Turkey's leaders.

"Fanaticism and fundamentalism, as well as irrational fears, which foster misunderstanding anddiscrimination, need to be countered by the solidarity of all believers," he said.

The world is morally obligated to help Turkey care for the great number of refugees it has taken in,Francis said.

Erdogan criticizes Islamophobia

In an address given in Francis' presence, Turkish President Recep Tayyip Erdogan highlighted whathe said was a disturbing trend of increased racism and Islamophobia in the West, while Islamistextremism wracks parts of the Middle East.

The world must come together if it wants to combat terrorism, he said.

The Turkish leader also suggested the West should not turn a blind eye to abuses committed bySyrian President Bashar al-Assad while it pursues ISIS.

The timing of the Pope's visit, in this period of unrest, is extremely significant, Erdogan added,voicing hope that it would lead to an "auspicious era" of improved relations in the world.

CNN's Arwa Damon and Christabelle Fombu contributed to this report