The assault on the Catholic church left 35 dead in Madalla, near the Nigerian capital. A failed bombing also occurred near a church in the city of Jos, followed by a shooting that killed a police officer. The blast came a year after a series of Christmas Eve bombs in Jos claimed by Islamist militants killed 32.
Benedict didn't refer explicitly to the Nigerian bombings in his "Urbi et Orbi" speech, Latin for "to the city and to the world" in which he raises alarm about world hotspots. But in a statement, the Vatican called the attacks a sign of "cruelty and absurd, blind hatred" that shows no respect for human life.
Elsewhere, Christmas was celebrated with the typical joy of the season: In Cuba, Catholics had plenty to cheer as they prepared for Benedict's March arrival, the first visit by a pontiff to the Communist-run island since John Paul II's historic tour nearly 14 years ago.
"We have faith in God that we will be allowed to have this treat," said Rogelio Montes de Oca, 72, as he stood outside the Cathedral in Old Havana. "Not every country will have the chance to see him physically and receive his blessing."
And in the Holy Land, pilgrims and locals alike flocked to Jesus' traditional birthplace in numbers not seen since before the Palestinian uprising over a decade ago, despite lashing rains and wind.
"We wanted to be part of the action," said Don Moore, 41, a psychology professor from Berkeley, California, who came to Bethlehem with his family. "This is the place, this is where it all started. It doesn't get any more special than that."
The holy town of Bethlehem is no stranger to violence. Like the rest of the West Bank, it fell on hard times after the Palestinian uprising against Israeli occupation broke out in late 2000.
But as the violence has subsided, tourists have returned in large numbers. On Saturday, turnout for Christmas Eve festivities in Bethlehem was at its highest since the uprising began driving tourists away. An estimated 100,000 visitors streamed into Manger Square on Christmas Eve, up from 70,000 the previous year, according to the Israeli military's count.
The Holy Land and the entire Mideast were very much on Benedict's mind as he delivered his Christmas speech from the the sun-drenched loggia of St. Peter's Basilica. The 84-year-old pontiff appeared in fine form, just hours after celebrating a two-hour long Christmas Eve Mass that ended around midnight.
"May the Lord come to the aid of our world torn by so many conflicts which even today stain the earth with blood," Benedict said.
He said he hoped that the birth of Jesus, which Christmas celebrates, would send a message to all who need to be saved from hardships: that Israelis and the Palestinians would resume peace talks and that there would be an "end to the violence in Syria, where so much blood has already been shed."
He called for international assistance for refugees from the Horn of Africa and flood victims in Thailand, among others, and urged greater political dialogue in Myanmar, and stability in Iraq, Afghanistan and Africa's Great Lakes region, which includes Congo, Uganda and Rwanda.
After his speech, Benedict delivered Christmas greetings in 65 different languages, from Mongolian to Maori, Aramaic to Albanian, Tamil to Thai. He finished the list with Guarani and Latin, as the bells tolled from St. Peter's enormous bell towers.
In the piazza below, thousands of jubilant tourists and pilgrims, and hundreds of colorful Swiss Guards and Italian military bands mingled around the Vatican's giant Christmas tree and larger-than-life sized nativity scene.
In the U.K., the leader of the world's Anglicans, the Archbishop of Canterbury, said the summer riots in Britain and the financial crisis had abused trust in British society.
In his Christmas Day sermon, Rowan Williams appealed to those congregated at Canterbury Cathedral to learn lessons about "mutual obligation" from the events of the past year. He said Sunday that "the most pressing question" now facing Britain is "who and where we are as a society."
"Bonds have been broken, trust abused and lost," he said. Britain's royal family, meanwhile, celebrated Christmas with one notable absence. Queen Elizabeth II's husband Prince Philip remained hospitalized after having a coronary stent put in after doctors determined the heart pains that sent him to the hospital on Friday were caused by a blocked artery.
Elizabeth's annual Christmas message dealt with the theme of family. The message was recorded Dec. 9, before Philip went into the hospital.
Wearing a festive red dress, the Queen said that the importance of family was driven home by the marriages of two of her grandchildren this year. Elizabeth spoke of the strength family can provide during times of hardship and how friendships are often formed in difficult times.
She pointed to the Commonwealth nations as an example that family "does not necessarily mean blood relatives but often a description of a community."
And in the United States, members of the loose-knit hacking movement known as "Anonymous" claimed to have stolen a raft of e-mails and credit card data from U.S. security think tank Stratfor, promising a weeklong Christmas-inspired assault on targets including the U.S. Army, the U.S. Air Force, Goldman Sachs and MF Global.
The group has previously claimed responsibility for attacks on companies such as Visa, MasterCard and PayPal, as well as others in the music industry and the Church of Scientology.