Responding to a list of "offenses" presented to him by Greece's Orthodox leader Archbishop Christodoulos, Pope John Paul II today asked God's forgiveness for Roman Catholic sins against the Orthodox faith during the last 1,000 years. The pontiff is on the first leg of a six-day pilgrimage in the footsteps of Saint Paul, the apostle who converted to Christianity on the road to Damascus. The Pope's visit to Greece, the first since the schism of 1054, was preceded by considerable protest by members of the Greek Orthodox clergy as well as tense and detailed negotiations. John Paul will spend only 24 hours in Greece, and previous plans to hold mass tomorrow in a large 80,000-seat stadium were scaled back to an 18,000-seat indoor arena. The Pope has repeatedly expressed his desire to end the rupture between the churches but this will not occur in the forseeable future. Orthodox Christians do not recognize the Pope as the leader of world Christianity and hold numerous grievances with the Catholic Church. Perhaps the most important of these, at least symbolically, is the sacking of Orthodox Constantinople by crusaders in 1204, an act which the Pope declared filled today's Catholics with "deep regret." Tomorrow John Paul will leave for Syria, where he will become the first Pope to enter a Mosque, and after four days there, he will complete his trip in Malta.