Greek Orthodox clergymen in Bethlehem hold Christmas Mass on Sunday at the Church of the Nativity - where Christians believe Jesus was born. The Greek Orthodox Mass is held on the second day of Christmas. This year, it's led by Patriarch Theofilos III of Jerusalem. He arrived in the West Bank on Friday to lead midnight Mass on Orthodox Christmas Eve. Eastern Christian churches include the ancient Assyrian Church, Greek and Russian Orthodox, Armenian and the Coptic Church.