Vatican City ? Pope John Paul II ushered in Christmas today by celebrating Midnight Mass at St. Peter’s Basilica, praying that world leaders will strive for peace and that Jews, Muslims and Christians will live harmoniously in the Holy Land.

All through the day, pilgrims descended on St. Peter’s Square to admire a 105-foot-tall Christmas tree brought down from the Italian Alps and a life-size Nativity scene unveiled Friday alongside the 100-year-old fir.

Many people waited in line for hours to get into the Mass while Italian police screened pilgrims with metal detectors before letting them into St. Peter’s Basilica. Police cars ringed the piazza, and officers patrolled the already heavily protected square in a fleet of new mini Lamborghinis resembling golf carts.

A choir sang a Christmas concert in the square after dusk. In the darkness, a single candle representing peace appeared in John Paul’s window, casting a soft light over the pope as he gazed onto the square. The pontiff raised the candle to make the sign of the cross, and the crowd burst into applause.

At Mass later, the ailing, 84-year-old pope was guided to the front of the church in his white wheeled throne. Wearing a pale golden robe, he appeared in form and spoke in a clear voice in his opening greeting.

The pope made no specific references to current issues in his homily, but said of Christ: “All humanity, with its burdens of trials and troubles, stands in need of you.”

“Stay with us, living bread which came down from heaven for our salvation! Stay with us forever.”

The service in the poinsettia-filled basilica also included prayers that world leaders dedicate themselves to peace and that Christians, Muslims and Jews live peacefully together in the Mideast.

“May (the Holy Land) experience times of prosperity and peaceful coexistence, through the mutual respect of its inhabitants,” said one of the Mass intentions. “May it be a safe place, and hospitable to pilgrims and truth-seekers.”

Today John Paul will read his holiday message and issue greetings in dozens of languages from the basilica balcony.