In his Jan. 20 video message, Pope Francis noted that 400,000 young adults had already registered to attend World Youth Day.

“It calls my attention and fills me with joy that so many young people will go to WYD, because they need to participate,” he said.

“Thank you for having already registered so far in advance,” the pope added. “Let’s hope others will follow your example.”

Francis said though some participants may claim they are only going to the event as tourists, rather than pilgrims, “deep down, he or she has the thirst to participate, to share, to tell their experience and receive the experience of others.”

He encouraged them to open their hearts to other cultures and to the other young men and women who will be there.

“Get ready for this: to open horizons, to open your hearts,” he said.

World Youth Day was established by Pope John Paul II in 1985. The meeting is typically held on a different continent every three years with the presence of the pope.

Lisbon, a city of 505,000 people, is approximately 75 miles from Fatima, one of the world’s most popular Marian pilgrimage sites.

Pope Francis is expected to attend the global Catholic gathering with stops in both Lisbon and Fatima.

The last World Youth Day was held in Panama in January 2019.