ISTANBUL (AP) -- Pope Francis stood Saturday for two minutes of silent prayer facing east in one of Turkey's most important mosques, a powerful vision of Christian-Muslim understanding at a time when neighboring countries are experiencing violent Islamic assault on Christians and religious minorities. His head bowed, eyes closed and hands clasped in front of him, Francis prayed alongside the Grand Mufti of Istanbul, Rahmi Yaran, in the 17th-century Sultan Ahmet mosque, shifting gears to religious concerns on the second day of his three-day visit to Turkey. "May God accept it," Yaran told the pope of their prayer. The Vatican spokesman, Rev. Federico Lombardi called it a moment of "silent adoration." Lombardi said Francis told the mufti twice that Christians and Muslims must "adore" God and not just praise and glorify him. It was a remarkably different atmosphere from Francis' first day in Turkey, when the simple and frugal pope was visibly uncomfortable with the pomp and protocol required of him for the state visit part of his trip. With President Recep Tayyip Erdogan's mega-palace, honor guard and horseback escort now behind him, Francis got down to the business of being pope, showing respect to Muslim leaders, celebrating Mass for Istanbul's tiny Catholic community and meeting with the spiritual leader of the world's 300 million Orthodox Christians. Francis bowed before Ecumenical Patriarch Bartholomew I and asked him "to bless me and the church of Rome" at the end of an ecumenical service Saturday evening. The Orthodox leader obliged, kissing Francis' bowed head. The two major branches of Christianity represented by Bartholomew and Francis split in 1054 over differences on the primacy of the papacy, giving particular resonance to Francis' display of deference. Francis' visit comes at an exceedingly tense time for Turkey, with Islamic State militants grabbing territory next door in Syria and Iraq and sending some 1.6 million refugees fleeing across the border. Some refugees were expected to attend Francis' final event on Sunday before he returns to Rome. Francis nodded, smiled and looked up in awe as Yaran gave him a tour of the Blue Mosque, famed for its elaborate blue tiles and cascading domes. Presenting the pope with a blue, tulip-designed tile, Yaran said he prayed to God that his visit would "contribute to the world getting along well and living in peace." "We are in need of prayers. The world really needs prayers," Yaran said. Francis was following in the footsteps of Pope Benedict XVI, who visited Turkey in 2006 amid heightened Christian-Muslim tensions over a now-infamous papal speech linking violence with the Prophet Mohammed. The Vatican added the stop at the Blue Mosque at the last minute to show Benedict's respect for Muslims, a gesture that was greatly appreciated by Turks. The Vatican also acted to avoid offense to its Muslim hosts this time around by moving up Francis' visit to the mosque so it wouldn't coincide with noon prayers. After he left, Francis walked a short distance to tour the nearby Haghia Sofia, which was the main Byzantine church in Constantinople -- present-day Istanbul -- before being turned into a mosque following the Muslim conquest of the city in 1453. The Haghia Sophia is now a museum, although some Islamic groups want it to be converted back into a mosque. Pope Paul VI, who made the first-ever papal visit to Turkey in 1967, fell to his knees in prayer inside Haghia Sophia, triggering protests by Turks who claimed Paul had violated the secular nature of the domed complex. Francis avoided any religious actions inside. Halfway through his tour, the Muslim call for prayer echoed off Haghia Sophia's marble walls, an evocative moment that symbolized the crossroads of the Ottoman and Roman empires, East and West, which Istanbul represents. Museum director Hayrullah Cengiz pointed to a niche with a Byzantine fresco of the Virgin Mary holding an infant Jesus, saying it was his favorite corner because the area also features Arabic writings of the names of the Prophet Mohammed and Allah. "They are all together," Cengiz said. Later Saturday, Bartholomew and Francis presided over an ecumenical prayer service at the Orthodox patriarchate on the eve of the feast of St. Andrew which both will celebrate Sunday. Their embrace at the end of Saturday's service was reminiscent of their meeting in May in the Church of the Holy Sepulcher in Jerusalem, when Francis bowed down and kissed Bartholomew's hand.