SEOUL, South Korea — Pope Francis on Saturday beatified Korean martyrs Paul Yun Ji-chung and 123 companions, praising their “great sacrifices” and their call “to put Christ first.”

“All of them lived and died for Christ, and now they reign with him in joy and in glory,” the Pope said during Mass at Seoul’s Gwanghwamun Gate.

“The victory of the martyrs, their witness to the power of God’s love, continues to bear fruit today in Korea, in the Church, which received growth from their sacrifice,” the Holy Father told a congregation of tens of thousands.

“Our celebration of Blessed Paul and Companions provides us with the opportunity to return to the first moments, the infancy as it were, of the Church in Korea. It invites you, the Catholics of Korea, to remember the great things which God has wrought in this land and to treasure the legacy of faith and charity entrusted to you by your forebears.”

Korean Christianity dates back to the 18th century, when Korean scholars heard about the spread of the faith in China. They traveled to China to study the Christianity under Jesuit missionaries. They returned to their homeland to teach the faith, gaining thousands of converts even in the absence of priests.

Korean authorities began to persecute Christians and prohibited Catholic books.

Paul Yun Ji-chung and James Kwong Sang-yon, both Catholics from a noble background, were beheaded in 1791 for violating Confucian rituals. Their execution marked the start of a major persecution of Korean laity.

Only one priest, from China, was among the 124 martyrs beatified Saturday.

The Pope’s official declaration of the martyrs’ beatification prompted loud cheers from the crowd as trumpets and drums sounded in Gwanghwamun Square. The massive television screens that flanked the altar displayed paintings of the martyrs.

Pope Francis’ homily said the origins of Korean Christianity show “the importance, the dignity and the beauty” of lay Catholics’ vocations.

“In God’s mysterious providence, the Christian faith was not brought to the shores of Korea through missionaries; rather, it entered through the hearts and minds of the Korean people themselves,” he said. “It was prompted by intellectual curiosity, the search for religious truth. Through an initial encounter with the Gospel, the first Korean Christians opened their minds to Jesus. They wanted to know more about this Christ who suffered, died and rose from the dead.”

Other Korean martyrs have been recognized as saints. St. John Paul II canonized 103 Korean martyrs on May 6, 1984, during a visit to South Korea.

Pope Francis invoked these saints, Andrew Kim Taegon, Paul Chong Hasang and Companions, along with the newly beatified martyrs during his homily.

The Pope discussed the Gospel reading from the 17th chapter of the Gospel of John and its relevance to the newly beatified martyrs.

“It is significant that, while Jesus asks the Father to consecrate and protect us, he does not ask him to take us out of the world,” Pope Francis said. “We know that he sends his disciples forth to be a leaven of holiness and truth in the world: the salt of the earth, the light of the world. In this, the martyrs show us the way.”

Korea’s martyrs “had to choose between following Jesus or the world,” he said. “They knew the cost of discipleship.”

“They were willing to make great sacrifices and let themselves be stripped of whatever kept them from Christ — possessions and land, prestige and honor — for they knew that Christ alone was their true treasure,” the Pope continued.

The Pope noted the temptation “to compromise our faith, to water down the radical demands of the Gospel and to conform to the spirit of this age.”

“Yet the martyrs call out to us to put Christ first and to see all else in this world in relation to him and his eternal kingdom. They challenge us to think about what, if anything, we ourselves would be willing to die for.”

Pope Francis closed his homily with a prayer:

“May the prayers of all the Korean martyrs, in union with those of Our Lady, Mother of the Church, obtain for us the grace of perseverance in faith and in every good work, holiness and purity of heart and apostolic zeal in bearing witness to Jesus in this beloved country, throughout Asia and to the ends of the earth.”