Rome, Italy - Roman Catholics embarked Sunday on a new year with a new pope, who used the day's festivities to urge stronger faith in God as a way to make peace in a world threatened by "terrorism, nihilism and fanatic fundamentalism.''
Benedict XVI, presiding over the first New Year's Day program of his papacy, led a morning Mass inside St. Peter's Basilica and afterward addressed thousands of pilgrims gathered in the square outside. The Vatican marks Jan. 1 annually by celebrating the World Day of Peace, a theme infusing Benedict's comments Sunday.
"A leap of courage, and of faith in God and in mankind,'' the pope said, are critical to promoting global peace.
It is the duty of everyone, of individuals, world powers and international organizations, to take up the cause, he said, singling out the United Nations and its responsibility to further justice and solidarity in the face of globalization.
"Faced with situations of injustice and violence that continue to oppress many regions of the planet, there exist new and even more insidious threats to peace -- terrorism, nihilism and fanatic fundamentalism -- that make it all the more necessary to work together for peace,'' Benedict said.
Dressed in a gold miter and snow-white robes, his trademark red leather shoes poking out from beneath, the pope directed Mass inside the marble walls of the basilica, before an audience that included diplomats, bishops and cardinals.
Later, in an address from the window of his apartment overlooking St. Peter's Square, Benedict again stressed the link between profound faith and the ability to foster peace. He then read short messages of salutation in an assortment of languages to the crowd, a drenched bunch huddled beneath colorful umbrellas raised against the driving rain.
In observance of World Peace Day, the pope also released a 16-point address, one of his key speeches of the year, that exhorted the world's peoples to end armed conflicts and the nuclear arms race, and to respect international humanitarian law that forbids, among other things, the torture and illegal detention of suspects.
The speech was released in December but dated Jan. 1, 2006.
Despite the "deadly and senseless strategies'' of terrorists, people engaged in the fight against terrorism must not forget the basic laws of human rights, the pope said. While Benedict did not mention a specific country, his comments came at a time when Europe is consumed with reports over U.S. use of secret prisons and allegations of abuse inside U.S. detention facilities.
"International humanitarian law ought to be considered as one of the finest and most effective expressions of the intrinsic demands of the truth of peace,'' the pope said. "Precisely for this reason, respect for that law must be considered binding on all peoples.''
In assessing the state of conflicts worldwide, he said there were signs of some progress in parts of the Middle East and Africa, but that these developments should not lead to "naive optimism.''
"It must not be forgotten that, tragically, violent fratricidal conflicts and devastating wars still continue to sow tears and death in vast parts of the world,'' he said. "Situations exist where conflict, hidden like flame beneath ashes, can flare up anew and cause immense destruction.''