Pope John Paul II began Easter Sunday Mass with a call to the faithful to work tirelessly for peace, as tens of thousands of people jammed rain-soaked St. Peter's Square for the service. John Paul took his place under a canopy erected on the steps of St. Peter's Basilica after only a few hours of rest after presiding over a three-hour-long Easter vigil ceremony Saturday night in the basilica. He looked pale and weary, at one point yawning and cradling his head in his hands. John Paul told some 50,000 tourists, pilgrims and Romans that Easter brings peace that only the Lord can give, and he urged faithful to be "tireless workers of peace in justice and truth."