Pilgrims and onlookers have gathered in Sydney's CBD for the Stations of the Cross, the re-enactment of the last days of the life of Jesus Christ.
About 80 performers are taking part in the re-enactment as part of Friday's World Youth Day celebrations.
The first station is in front of St Mary's Cathedral, where Pope Benedict will join pilgrims and special guests to watch a theatrical depiction of the last supper.
World Youth Day spokesman Father Mark Podesta says up to 1 billion people around the world will tune in to watch the performance.
"It's sure to be moving and inspiring and probably the event that people will remember for years to come after World Youth Day," he says.
The Stations of the Cross dates back to the early days of the Christian Church, when pilgrims visited Jerusalem to carry out a similar ritual.
Pope Benedict is expected to meet with a group of disadvantaged youth later this evening.