Pope Francis, left, and Ecumenical Patriarch Bartholomew I sign a joint declaration, in Istanbul, Sunday, Nov. 30, 2014. Pope Francis and the spiritual leader of the world's Orthodox Christians, Ecumenical Patriarch Bartholomew I, issued a joint declaration Sunday at the end of Francis' visit to Turkey during which the pope prayed in one of Istanbul's most important mosques. They wrote: "Inspired by common values and strengthened by genuine fraternal sentiments, Muslims and Christians are called to work together for the sake of justice, peace and respect for the dignity and rights of every person." (AP Photo/Filippo Monteforte, Pool)