Pope Francis on Saturday celebrated a huge open-air Mass in the center of Seoul, where he denounced the growing gap between the haves and have-nots, urging people in affluent societies to listen to "the cry of the poor" among them.
The pope made his remarks in the homily of a Mass where he beatified 124 Korean martyrs who were killed in the 18th and 19th centuries for refusing to renounce Christianity.
Beatification is the last step before sainthood in the Roman Catholic Church.
In his homily before a crowd of hundreds of thousands, many of whom had waited for hours on a steamy morning, Francis said the martyrs' courage and charity and their rejection of the rigid social structures of their day should be an inspiration for people today.
"Their example has much to say to us who live in societies where, alongside immense wealth, dire poverty is silently growing; where the cry of the poor is seldom heeded and where Christ continues to call out to us, asking us to love and serve him by tending to our brothers and sisters in need," he said.
It was a theme the pope has been repeating since he arrived in South Korea on Thursday for his first trip to Asia since his election in March 2013, and has been a lynchpin of the papacy of the first non-European pontiff in 1,300 years.
Last year, in the first major written work of his papacy, Francis attacked unfettered capitalism as "a new tyranny", urging global leaders to fight poverty and growing inequality.
Rapid economic growth has made South Korea one of the world's wealthiest countries, but it has also become increasingly unequal, with nearly half the elderly in poverty.
Kim Jong-doo, a 57-year-old Catholic who attended Saturday's mass, said the wealth gap is a reality of South Korea.
"Although religious leaders point it out all the time, there is no change. Nothing is working out. Government really needs to take some actions to bring changes but that is not being done here," he said.
Prayer for ferry victims
The pope said the Mass from a white altar platform in front of Gwanghwamun Gate, where some of those beatified by Francis were killed during the Chosun dynasty.
During his long procession to the altar, Francis stopped to kiss babies as members of the festive crowd pressed closer. Many in attendance wore t-shirts with an image of Francis on them.
He also stopped to pray with family members of victims of this year's Sewol ferry disaster. They had gathered under a tent with a sign saying: "We want the truth. You love those suffering, Papa! Sewol families are here!"
One handed Francis a letter and said: "please do not forget."
The Sewol ferry sank during a routine voyage on April 16, killing more than 300 people, most of them children on a school outing, a tragedy that left the country grieving and outraged and prompted a backlash against the government of President Park Geun-hye over its handling of the disaster.
As he did on Friday when he prayed for the victims, survivors and families of the disaster, the pope wore a yellow ribbon, the symbol of tribute for the ferry victims.
The history of Christianity in Korea is unique in that it was not founded by Western missionaries. Korean intellectuals in the late 18th century heard about it through literature that had arrived in the country from China and developed their own community.
The Catholic Church has been growing rapidly in South Korea, doubling in the past 25 years to about 11 percent of the population, adding some 100,000 new members every year.