In Iraq, Christians made their way past checkpoints Tuesday to fill Baghdad churches in numbers unthinkable a year ago. And in the West Bank town of Bethlehem, where tradition says Jesus was born, Christians celebrated in an atmosphere of hope raised by the renewal of Israeli-Palestinian peace talks.
For them, and for all those in the "tortured regions" of the world, Pope Benedict XVI prayed that political leaders would find "the wisdom and courage to seek and find humane, just and lasting solutions."
Benedict, delivering his Christmas Day address from the central balcony of St. Peter's Basilica, urged the crowd to rejoice over the celebration of Christ's birth, which he hoped would bring consolation to all people "who live in the darkness of poverty, injustice and war."
In violence-ridden Baghdad, venturing out in large numbers late at night is still unthinkable, so the Iraqi capital's Christians celebrated Midnight Mass in the middle of the afternoon on Christmas Eve.
On Tuesday some 2,000 went out to the Mar Eliya Church in the east of Baghdad where Iraq's Cardinal Emmanuel III Delly, leader of the ancient Chaldean Catholic Church, celebrated Mass.
He told the congregation that Iraq is "a bouquet of flowers of different colors, each color represents a religion or ethnicity but all of them have the same scent."
He congratulated Muslims for their Eid al-Adha holiday, falling near Christmas, and Muslim clerics -- both Sunni and Shiite -- attended the service in a sign of unity.
"May Iraq be safe every year, and may our Christian brothers be safe every year," Shiite cleric Hadi al-Jazail told AP Television News outside the church. "We came to celebrate with them and to reassure them. ... This national gathering is beautiful against the sectarian fighting, and God willing from this lesson we'll all pray for peace."
Christian pilgrims in Bethlehem filled the ancient Church of the Nativity, waiting in line to see the grotto that marks the traditional birthplace of Jesus.
The large numbers and the cacophony of languages was evidence that more visitors were there this year than in the past several years.
The outbreak of the Palestinian uprising against Israel in late 2000 and the fighting that followed had clouded Christmas celebrations in Bethlehem for years, battering the tourism industry that is the city's lifeline.
Kiel Tilley, 23, a science teacher from Charlevoix, Mich., said the relaunch of Israeli-Palestinian peace talks at a U.S.-sponsored conference last month reassured him before his trip to Bethlehem. "The peace process made me feel safer."
The experience, he said, was "very powerful and meaningful to me. ... It's very moving to visit a place which I always read about in the Bible."
In Afghanistan, British soldiers stationed in Helmand province found a little joy far from home at a meal where they wore red Santa hats and opened gift boxes. And U.S. service members went to early Christmas Mass at a base in Kabul.
Britain's Queen Elizabeth II spoke to the nations of the Commonwealth in a televised Christmas message, urging people to think of the needs of the vulnerable and disadvantaged living on the edge of society.
During a service at Canterbury Cathedral, the Archbishop of Canterbury Rowan Williams, the spiritual leader of the 77 million-member Anglican Communion, urged his flock to protect the environment -- saying that "human greed" threatened to distort the Earth's fragile balance.
In Belgium, where a terrorism alert on Friday led to a security clampdown, police kept up a visible presence in downtown Brussels and in busy shopping malls on Christmas Eve.
Belgium's king, Albert II, urged reconciliation between French- and Dutch-speakers after a six-month political crisis led to fears the country could split up.
Austrian President Heinz Fischer expressed concern about the division of wealth in society and the hardships people face because of illness, disability and unemployment.
In Puerto Rico's colonial district of Old San Juan, locals sang and rattled maracas along cobblestone streets, celebrating a Puerto Rican-style caroling known as the "parranda." People hosted revelers with holiday cookies and coquito, a sweet seasonal drink made from rum and coconut.
Others enjoyed the holiday by heading to one of the U.S. Caribbean territory's palm-fringed beaches for a sun-soaked Christmas picnic.
President Bush planned a Christmas Day lunch with his family at the presidential retreat in the mountains northwest of Washington.
In the Philippines, a largely Roman Catholic nation of 89 million, weeks of yuletide preparations culminated on Christmas Eve with Mass before midnight, followed by a sumptuous dinner called "noche buena," that was capped with an exchange of gifts.
Christmas celebrations often are occasions for family reunions, and tens of thousands of Filipinos who work overseas booked flights to return home to be with their loved ones.
On Christmas Day, many families visited relatives, and in the capital, Manila, Filipinos flocked to Rizal Park for picnics.