The pope made several stops to greet children during a parade toward the altar for the Asian Youth Day closing mass on Sunday.
Thousands of people waved and cheered, despite the nasty weather, as the pope gave his blessings.
In the homily, he asked young Catholics to stay awake, saying that no one who sleeps can neither sing, dance nor rejoice.
"It's the duty to be vigilant, not to allow the pressures, the temptations and the sins of ourselves or others to dull our sensitivity to the beauty of holiness."
Around 45-thousand people, including 6-thousand young Catholics from 23 Asian countries. and Asian bishops, attended the mass at Haemi Fortress, where thousands of Korean Catholics were brutally executed in the 1800s.
The mass proceeded in many languages, including Indonesian, Japanese and Korean.
It was an unforgettable day for many of the participants.
"In between, there was one part where he said, 'Do not be afraid, be brave,' and at the end he said, 'Asian youth, wake up.' That really gives us a lot of energy."
"I feel blessed and honored of course to be part of this big event. It's a once-in-a-lifetime chance to meet the pope and other young people in Asia."
Asian Youth Day is a gathering of young Catholics, where they can explore and renew their faith.
The first one was held in Thailand in 1999.
"The Sixth Asian Youth Day that took place here in Korea was the first to be attended by the pope.
The seventh Asian Youth Day will take place in Indonesia in 2017.
Hwang Ji-hye, Arirang News, Seosan.