This Christmas Eve, hundreds of thousands of pilgrims are expected to flock to Rome for the start of the yearlong Jubilee, a rare Catholic tradition during which believers can have their sins forgiven.

A fraction of that — perhaps a few hundred intrepid souls — are likely to make the pilgrimage to Bethlehem, where some theologians say Christianity began with the birth of Jesus.

The contrast between two of the most important cities in Christianity could not be starker at the start of this Jubilee, which is traditionally celebrated only every 25 years. It is a tale of one city that is spending billions of dollars to move itself into the future, eager to show off its unique history with progressive comforts, and another that is mired in a generations-long war where its 34,000 residents struggle to earn a living wage.

In Rome, plywood construction walls and scaffolding temporarily surround landmarks, as workers race to spruce up the city in time for the flood of visitors from around the world.

A different kind of wall, of gray concrete and standing nearly 40 feet high, confronts visitors to Bethlehem, a Palestinian city in the Israeli-occupied West Bank, where signs at security checkpoints warn Israelis that entering the area is forbidden and “dangerous to your lives.”

A highlight of the Jubilee in Rome is to pass through the so-called Holy Doors of at least one of four Catholic basilicas designated by the Vatican to receive plenary indulgence — the forgiveness of sins and removal of any afterlife punishment linked to them.