The Chicago-born pope addressed a crowd of 30,000 in a live-streamed message from the Vatican: "Build up community [and] friendship as brothers and sisters."

Supporters of Pope Leo XIV gathered Saturday, not in a cathedral or a church, but a baseball stadium the pope once frequented years as Robert Francis Prevost.

The pope urged Catholic faithful to be a "light of hope," to serve others, and to make the world a better place.