TAEGU, South Korea — Pope John Paul II Saturday addressed a nation-wide youth congress and told thousands of cheering young people that they must live fully for both themselves and the world.

"You are young and you want to live," John Paul said, as stands in Taegu Citizen's Stadium appeared snow-covered with prayer shawls. "But you must live fully and with a purpose. You must live for God, you must live for others ... the future is yours, full of perils and possibilities, hope and anguish, suffering and happiness."

A different kind of crowd heard the 63-year-old pontiff on his third day here to mark the 200th year of Catholicism in Korea — a young one that clapped and stomped as songs of love and hope were trilled.

His own message was still of peace and brotherhood as it was the night before in Seoul. John Paul then called for a new order of international morality and said that "naked terrorism" such as the Rangoon bombing by North Korean agents last year can only threaten peace and cripple hopes for a better world.

Referring to last year's murder of Korean cabinet officials in Rangoon, the pontiff told the Seoul diplomatic corps that world leaders and diplomats must abandon self-seeking national interests and find "a new way of thinking.

"Peace!" John Paul declared. "Much is said about it. Yet genuine peace is ever more elusive. On the one hand, the instruments of war — tools of death and destruction — constantly increase. On the other hand, the available structures of dialogue, whether between the bigger nations and alliances or between the parties to limited and localized disputes, have shown themselves to be extremely fragile and vulnerable. Should we then cease to speak out about peace?"

The only way to peace, John Paul said, is for people and governments to undergo "conversion of heart that restores reverence for human dignity and stops subordinating this to preconceived interests and to the ambition of power in any of its forms."

The pope appealed to the diplomats to use all the means they have to promote "sincere dialogues and mutual collaboration" for a just world order.

"Today, here in Seoul," he said, "I take this opportunity to ask you, the members of the diplomatic corps, and I wish to extend this appeal to all men and women in positions of responsibility, to work for peace by working for a change of heart, by striving to view the world situation with a fresh outlook and with the will to overcome old prejudices and one-sighted views."

He added that a global atmosphere of suspicion exists now, causing feelings of insecurity that raise obstacles to peace.

"This leads, in turn, to ever-higher levels of tension aggravated by the inevitable search by every means and by all sides to ensure military superiority, even to gain the upper hand by acts of terrorists — as in Rangoon — or predominance through economic and ideological control. The aspirations of hundreds of millions of human beings for a better life, the hopes of the young for a better world, will inevitably be frustrated unless there is a change of heart and a new beginning!"

Earlier, John Paul said an open-air Mass for 65,000 worshippers in Kwangju, south of Seoul, and then was flown to Sorokdo Island, abandoning his bullet-proof vehicle to walk freely among lepers.

Landing on a field thickly fringed by poplar and pine, he first turned to a flutter of golden color — the papal flags held in hands crippled by a disease that gradually erodes the body — John Paul shook one warped hand and touched easily the heads of those still scorned as "untouchables" in much of the world.

He then climbed into a limousine and was driven a short distance across the island where 2,308 lepers and 250 doctors and nurses live.

"Many lepers try suicide," said Dr. Shin Yong Shik, who directs the island hospital and told Pacific Stars and Stripes that the pope's visit answered a personal appeal he wrote to the Vatican.

"It's a very hard time," he said. "Then they come here and get religion. They are Christian."

There are two Catholic and seven Presbyterian churches on island, and priests and ministers from all — along with a Buddhist monk who suffers himself from the disease — turned out to greet the pontiff as he walked through a slight rain and entered a small chapel.

There he again touched the afflicted and the nurses' choir sang as applause sounded from patients not yet heavily stricken by the sickness that can sometimes be arrested, but not cured.

"It is necessary for you to know that Christ is particularly close to you," John Paul told them. "In this gospel of suffering we find praise for those who have persevered in the midst of the trials of suffering. We read: `You had heard of the steadfastness of Job and you have seen the purpose of the Lord, but the Lord is compassionate and merciful.' "

John Paul was to celebrate Mass before thousands Saturday in the southern city of Taegu and many Americans from nearby military bases planned to attend. On Sunday, in Seoul's Yoido Plaza, he will canonize 103 missionaries and converts killed as the faith struggled to survive here in its earlier years. John Paul journeyed to Seoul to mark the 200th year of Catholicism in Korea.