VATICAN CITY -- Pope Benedict XVI personally greeted the most powerful prelates in the church yesterday in a ceremony that illuminated two central elements of the new papacy: his vast Vatican experience and his efforts to cement bonds with his beloved predecessor.
One by one, more than 150 cardinals kissed the pontiff's hand and chatted briefly with him under the sweeping frescoes in the Clementine Hall, where mourners first saw John Paul II's body after his death April 2. The encounters with the new pope were easy and familiar.
Meanwhile, Rome officials continued to gear up for the installation of the pope tomorrow. The outdoor Mass in St. Peter's Square is expected to draw hundreds of dignitaries, including presidents, prime ministers, and religious leaders.
Half a million faithful also are expected, about 100,000 of them from the pontiff's native Germany.
The pontiff had served in a highly influential Vatican post since 1981 and is well known by nearly all the cardinals and members of the Vatican bureaucracy -- a sharp contrast to John Paul's arrival in 1978 as a Vatican outsider with few established confidants. Benedict has moved quickly to reappoint the entire top leadership of the Holy See, which he helped shape as one of John Paul's key advisers.
The pope also has repeatedly cited John Paul's legacy and his desire to continue in its spirit.
Benedict told the cardinals the late pope's ''great trial and suffering" against Parkinson's disease and other ailments were an inspiration for all Roman Catholics.
On Thursday, he reinforced another link important to John Paul: close contact with Rome's Jewish leaders.
''I undertake this new mission with more serenity because I am able to count on your generous collaboration in addition to the indispensable help of God," he told the cardinals. He was elected Tuesday by 114 of his fellow cardinals under age 80.
The cardinals came one by one and knelt before the pope, who was wearing all-white robes and seated on a gilded chair. He exchanged a few words with each, but spent longer with Cardinal Karl Lehmann, president of the German Bishops' Conference. The pope responded with gestures that may become familiar to the world as his papacy evolves: raising his eyebrows while listening and flashing a quick smile.
The 78-year-old pope rose to welcome the cardinals unable to kneel, including 86-year-old American theologian Avery Dulles and Andrzej Maria Deskur of Poland, who uses a wheelchair.
The pope's initial words and acts are forcing a wider reassessment among followers. Many feared a distant and strident papacy because of the pontiff's long role as the church's main watchdog of theology, an office responsible for muzzling and punishing dissident voices.
''Already Benedict XVI has become . . . an 'open door' pope, cordial and spontaneous," said Donatella Pacelli, a Rome sociologist who studies Catholic issues.
The pope's Vatican e-mail addresses received more than 56,000 messages in the first two days, with many well-wishers asking when he will visit their countries.
But before any travel can be considered, he must formally take the papal throne.
The Mass in St. Peter's Square tomorrow is expected to draw 500,000 people and Rome officials planned very tight security, including antimissile systems, fighter jets, and surveillance planes. Air space within a five-mile radius will be closed from 8 a.m. to 4 p.m. tomorrow, and Rome's second airport, Ciampino, will be shut.
Dignitaries expected to attend will include Chancellor Gerhard Schroeder of Germany; Prince Albert II of Monaco; and Archbishop of Canterbury Rowan Williams. Florida Governor Jeb Bush will lead the United States delegation.
Known as the Ceremony of Investiture, it will celebrated by the senior cardinal deacon, Jorge Arturo Medina Estevez, the Chilean who proclaimed Benedict's name to the world as the 265th pontiff.
During the Mass, Benedict will receive his papal Fisherman's Ring as well as the pallium -- a narrow stole of white wool embroidered with six black silk crosses -- which symbolizes his pastoral authority.
The choice of an outdoor Mass, rather than in St. Peter's Basilica, shows Benedict favors the populist touch of recent popes who have made the same choice.
Italian civil protection chief Guido Bertolaso told reporters that the pope would likely mingle with the faithful.