PORT-AU-PRINCE, Haiti -- With their churches flattened, their priests killed and their Bibles lost amid the rubble of their homes, desperate Haitians prayed in the streets on Sunday, raising their arms in the air and asking God to ease their grief.

Outside the city's main cathedral, built in 1750 but now a giant pile of twisted metal, shattered stained glass and cracked concrete, parishioners held a makeshift service at the curb outside, not far from where scores of homeless people were camping out in a public park. The bishop's sermon of hope was a hard sell, though, as many listening had lost their relatives, their homes and their possessions.

"We have to keep hoping," said Bishop Marie Eric Toussant, although he acknowledged that he had no resources to help his many suffering parishioners and did not know whether the historic cathedral would ever be rebuilt. He said last week's earthquake had toppled the residences where priests stayed, crushing many of them.

Baptized at the cathedral, Jean Viejina, 68, said she had visited the church every Sunday morning for as long as she can remember, using it to help her endure what she described as a challenging life raising six children. Now, even this place of refuge, like so much in Port-au-Prince, was gone.

In a sign of the importance of churches in Haitian society, President René Préval called together religious and business leaders Saturday at the police station that has become his headquarters. He asked the churches to focus on keeping people fed, but gave little guidance on what the government would be doing.

"They are still trying to figure out what to do," said Haiti's Episcopal bishop, Zache Duracin. "I have not seen anything."

Ban Ki-Moon, the United Nations secretary general, arrived to offer a promise of improvement from his organization, which was badly hit itself by the quake but still heavily criticized for the slow pace of the emergency response.

"I am here with a message of hope that help is on the way," Mr. Ban told a crowd of Haitians in front of the severely damaged National Palace.

Lt. Gen. P.K. Keen, the deputy commander of the United States Southern Command who is overseeing military relief, said in an interview Sunday on NBC's "Meet the Press" that "we had a good day yesterday," with 1,000 American military personnel on the ground in Haiti and 3,000 others on ships offshore delivering 130,000 rations and 70,000 bottles of water.

Calling the catastrophe "a disaster of epic proportions," he said that American soldiers there are trying to balance security and the urgency of delivering supplies swiftly. "Our experience there is there is calm on the streets," General Keen said.

Rajiv Shah, director of the U.S. Agency for International Development, said on the same program that three water purification units had been put into operation and were producing 100,000 liters of clean water a day. Search and rescue teams in Port-au-Prince had managed "dozens of successes" in pulling survivors from the rubble of collapsed buildings, he said.

Former Presidents George W. Bush and Bill Clinton, who were appointed by President Obama to raise funds for relief through the Clinton-Bush Haiti Fund, made the rounds of the Sunday morning television news programs to discuss the needs in Haiti. President Bush said one of the lessons that previous disasters like Hurricane Katrina taught him is that "it takes time to get supplies in."

Mr. Clinton was scheduled to travel to Haiti on Monday to meet with officials and deliver supplies, his foundation announced.

Some nongovernmental groups have complained of airplanes with important supplies -- including an inflatable field hospital brought byDoctors Without Borders -- being diverted because of backups in Port-au-Prince, caused partly by the military's heavy use of the airport.

Colonel Buck Elton, commander of the Southern Command for south Haiti, said Sunday that military air controllers were working hard to get as many aircraft into and out of the Port-au-Prince airport as possible. On Saturday, three of 67 incoming flights were diverted. So far on Sunday, two flights had been diverted.

"Our intent is as soon as one aircraft departs, another one arrives," he said in a conference call from Port-au-Prince arranged by the White House. Despite challenging circumstances, he said, "it gets better every day."

In Port-au-Prince on Sunday, some people seemed far too concerned with survival, or too confused, to think about church. One young man living in the park across from the presidential palace with thousands of others made homeless looked puzzled when asked if he would be going to church.

"Is it Sunday?" he said.

But other Haitians spent the morning searching for spiritual solace.

Carrying Bibles, they traversed the dusty streets on foot looking for outdoor prayer gatherings. Churches once full of passionate parishioners stood empty, if they stood at all.

At Holy Trinity Episcopal church, the world-renowned murals in the sanctuary had been reduced to rubble as drab as chalk. Only one wall stood, showing the baptism of Christ. The rest of Jesus Christ's life, as depicted by artists like Wilson Bigaud who displayed biblical figures with dark skin and tropical-colored clothes, were all destroyed.

Three older women arrived there around 9 a.m. looking for a service, wearing dresses that were remarkably clean and wrinkle-free.

The gathering they found, however, dealt with the physical and not the spiritual. More than 1,200 people were camping out in the soccer field of the campus, and in a grove of shade, a man with a megaphone and Latex gloves advised the group about hygiene.

"We need to make plans to pick up the garbage," he said.

The three women sat down at first, then moved on when an argument broke out about whether women would be allowed to use the priest's toilet.

Later, more people came and left, including Dorsainvil Joseph, 53, who carried a red leather Bible in his one good hand. The other looked broken. It was swollen, held up in a sling made of thin, white rope.

His head was wrapped in a bandage.

"We would like to pray, but we haven't found anyone," Mr. Joseph said.

Bishop Duracin said organization and survival were still the priorities for both people and institutions.

"Most of the churches are down," he said, estimating that more than 100 of the 140 Episcopal churches here had collapsed. "There is almost no place for worship or prayer."

People are afraid to go into buildings, including churches, that did not collapse, he said, including himself. His home was completely destroyed, so he was sleeping one of the red Coleman tents that he distributed to about 40 families.

He said that since the earthquake, he had not given a single sermon and was still trying to figure out what to say. When asked what parts ofthe Bible he had been contemplating lately, he answered quickly: "Job," he said.

Like Job, who persevered through death and destruction, Bishop Duracin said he hoped that Haiti would soon find a way to continue living.

"We have to look for opportunities from the disaster," he said. "We have to mourn. We have to suffer. But we have to get up because life has to continue."