A teenager — whose online teachings earned him the moniker of "God's influencer" — has become the first Millennial saint.

Carlo Acutis, who died in 2006, at the age of 15, has been canonised by Pope Leo at an open-air mass in St Peter's Square.

• Guest: Colm Flynn, Vatican Correspondent for EWTN Network
• Producers: Teodora Agarici and Grace Stranger