TOKYO — Magnetic and compelling, evangelist Billy Graham called upon 20,000 Japanese to turn Christian and warned them that conversion could be a costly thing that might mean conflicts with their families and friends.

Mindful that he was in a country where less than one percent of the population is Christian, Graham told a crowd that filled about half of Korakuen Baseball Stadium about the trials of a young Singaporean who had turned to Christianity.

Graham said that young man, a steward on an airliner, sat beside him and told of how he had been searching for something to believe when he heard a tape of a Graham sermon and went home to tell an angry family he had found a new faith. His brothers beat him and he was cast out of the family, Graham said.

Later, Graham said, the family itself saw the light and became Christian.

"My father is no longer drunk," Graham said the youth told him, "and my brothers are living good lives."

Without naming Charles Colson, Graham told of how the Watergate wiretapper accepted Christianity before going to prison and now preaches to convicts in penal institutions all over the United States. The composer of the hymn, "Amazing Grace," Graham said, was a slaver who became Christian after his life was spared in a storm, disdaining his former life as a "wicked man" to lead the fight against the slave trade.

"Who is this Jesus Christ who can do all this?" Graham asked, holding, up a Bible and calling it "the oldest book in the world," the solution to all the world's problems and every human man woe.

People everywhere, Graham said, are searching for a light out of troubled times.

"There are many in Japan and Africa and America," Graham said. "I've found the human heart to be the same all over the world."

Graham said the answer is in Christ, "God in the flesh" who walked the world.

Nevertheless, he added, a Japanese Christian has a hard way to go.

"It is costly to follow Christ," Graham said. "Are you willing to follow Christ? It may be like the man on the airliner. You may face problems with your family. Are you willing to do that? It may cause you trouble with your friends and your business. You have to want Christ that much."

Graham held the first of his outdoor services Wednesday in Tokyo, with the last scheduled Sunday at 3 p.m., in an arena that is home base for the Yomiuri Giants baseball team. Outside the main entrance, an amusement park was going full blast and there were excited squeals from riders on a roller coaster. Concessions hawked hot dogs and Giants pennants, competing with uniformed Salvation Army members who sold Japanese editions of Graham's books and tapes of his sermons.

Graham spoke from a platform covered with blue vinyl and decaled with his Crusade symbol — a cross in a beam of light. The same signet glittered on the scoreboard. A Crusade choir, made up of young people from local churches, filled a large block of seats.

Graham got a home-run cheer as he walked to the pulpit, speaking as the Rev. Noboru Hara translated his remarks. He ended his sermon by calling converts forward, asking them to come down four ramps that thrust out of the stands and were marked by blinking red lights like those on traffic markers. People poured down in a hesitant then steady flow, crowding the covered diamond from pulpit to home plate.

Graham told them to go home and tell their families and friends what they had experienced.

"Some of them may laugh," he said. "You may be shamed. But think of Jesus as the Christ."

Graham came here after preaching on Okinawa and the southern Japanese mainland.