AP

SEOUL, South Korea (AP) — Pope Francis beatified 124 Korean martyrs on Saturday, telling hundreds of thousands of people who turned out for his open-air Mass that their ancestors' willingness to die rather than renounce their faith two centuries ago was a model for Asian missionaries today.

The streets leading up to Seoul's iconic Gwanghwamun Gate were packed with Koreans honoring the lay Catholics who founded the church here in the 18th century. Korea's church is unique in that it was founded not by foreign missionary priests — as occurred in most of the world — but by members of Korea's own noble classes who learned of Christianity by reading books about it.

These early Catholics were killed in the 18th and 19th centuries by the Joseon Dynasty, which tried to shut the Korean Peninsula off from Western influence.

Police in Seoul declined to give an estimate of the crowd size, but the Vatican said about 800,000 people had turned out. The number was significant given that Catholics represent only about 10 percent of South Korea's 50 million people.

The Mass kicked off a busy day for Francis as he passed the halfway mark of his five-day South Korea visit. In the afternoon, he traveled to a religious community that cares for severely disabled Koreans and prayed briefly at a monument to aborted babies — a strong albeit silent gesture from a pope who prefers to stress other aspects of church teaching rather than emphasize hot-button "culture war" issues like abortion.

The Mass in Seoul, though, was one of the highlights of his trip, providing Francis with an opportunity to stress how the lessons of Korea's early martyrs were relevant today for Korea's church, which is small but growing and is seen as a model for the rest of the world.

"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," he said. "They challenge us to think about what, if anything, we ourselves would be willing to die for."

Francis praised in particular the fact that laypeople were so crucial to the church's foundation and growth in Korea — a theme he stressed later in the day when he met with leaders of Korean lay movements. The church is counting on such laymen and laywomen to spread the faith in Asia, which the Vatican considers the future of the church. The main reason for Francis' visit to South Korea, in fact, was to attend an Asian Catholic youth festival; the church sees such rallies as a crucial way of inspiring the next generation of Catholics to evangelize.

"Today as ever, the church needs credible lay witnesses to the saving truth of the Gospel," Francis said, stressing in particular the need for their outreach to focus on the poor and most marginalized.

A collective cheer erupted from the masses when Francis declared the 124 "blessed" — the first step toward possible sainthood. Many of the women in the crowd wore lace veils; others sported paper sun visors with "Papa Francesco" written across them, protecting them from the overcast, hazy skies.

The scene was impressive, with thousands of people neatly packed into fenced-in sections leading away from the altar, which was set up in front of Gwanghwamun, the south gate to Gyeongbokgung palace, with mountains looming above and the presidential Blue House on the lower slope. Police in green vests stood guard along the barricades and volunteers handed out water to guard against the warm, humid temperatures.

"I'm so thankful that the pope visited South Korea," said 75-year-old Yu Pil-sang, a Catholic who was trying to get a glimpse of Francis just outside the police barricades. "But I'm so sorry that all the ways to see the pope are blocked. I came to hear at least his voice."

En route to the altar before Mass, Francis stopped his open-topped car so he could get out and bless a group of families who lost loved ones in the sinking of the Sewol ferry in April, in which more than 300 people, most of them high school students, were killed. On his white cassock, Francis wore a yellow ribbon given to him by the families a day earlier when he met with them privately to try to console them.

"We want the truth," read a yellow banner, a reference to the families' demands for an independent inquiry into the sinking. Officials said 400 families had been invited to the Mass.

The main figure in the group that was beatified is Paul Yun Ji-Chung, who was born in 1759 and was among the earliest Catholics on the peninsula. He was beheaded in 1791 — the first Korean martyr — after he violated the traditional Confucian funeral rites for his mother. In all, the Joseon Dynasty killed about 10,000 Catholics for refusing to renounce their faith.

Historians say Korea's early believers were struck by the idea of a religion that preached universal equality in divine eyes at a time when the nobility's discriminatory hierarchical system brutally exploited ordinary people.

St. John Paul II canonized another 103 martyrs during a visit to South Korea in 1984. Francis began his day by praying at a monument in Seoul commemorating the martyrs on the site where many of them were killed.

Even non-Catholics turned out for the Mass, impressed by Francis' humble gestures and call for South Koreans to pay more attention to the poor than their own material gain.

"I do not know much about Catholics and South Korea's Catholic history, but it seems that the pope is making sure to reach out equally to everyone," said Eom Yae-sung, 49, a Protestant who said Francis had inspired her to make changes in her own life.

"I plan to do volunteering and a lot of sharing so that when I look back at my life 10 years from now, I will think that the pope's visit motivated me to change," Eom said.