VATICAN CITY, VATICAN - MARCH 29:  Pope Francis waves to the faithful as he leaves St. Peter's Square at the the end of Palm Sunday Mass on March 29, 2015 in Vatican City, Vatican. On Palm Sunday Christians celebrate Jesus' arrival into Jerusalem, where he was put to death. It marks the official beginning of Holy Week during which Christians observe the death of Christ before celebrations begin on Easter.  (Photo by Franco Origlia/Getty Images)