IN THE NUBA MOUNTAINS, Sudan — If you subscribe to the caricature of devout religious believers as mostly sanctimonious hypocrites, the kind who rake in cash and care about human life only when it is unborn, come visit the doctor here.

Dr. Tom Catena, 51, a Catholic missionary from Amsterdam, New York, is the only doctor at the 435-bed Mother of Mercy Hospital nestled in the Nuba Mountains in the far south of Sudan. For that matter, he’s the only doctor permanently based in the Nuba Mountains for a population of more than half a million people.

Just about every day, the Sudanese government drops bombs or shells on civilians in the Nuba Mountains, part of a scorched-earth strategy to defeat an armed rebellion here. The United States and other major powers have averted their eyes, so it is left to “Dr. Tom,” as he is universally known here, to pry out shrapnel from women’s flesh and amputate limbs of children, even as he also delivers babies and removes appendixes.

He does all this off the electrical grid, without running water, a telephone, or so much as an X-ray machine — while under constant threat of bombing, for Sudan has dropped 11 bombs on his hospital grounds. The first time, Dr. Tom sheltered, terrified, in a newly dug pit for an outhouse, but the hospital is now surrounded by foxholes in which patients and the staff crouch when military aircraft approach.

“We’re in a place where the government is not trying to help us,” he says. “It’s trying to kill us.”

Given the shortage of resources, Dr. Tom relies disproportionately on makeshift treatments from decades ago.

“This is a Civil War-era treatment,” he said, pointing to a man with a broken leg, which he was treating with a method known as Buck’s traction, using a bag of sand as a weight.

“Sometimes these actually work,” Dr. Tom said. “You use what you have.”

Pope Francis seems to be revitalizing the Vatican and focusing on the needy, and I have a dream — OK, an implausible one — that he’ll journey to this Catholic hospital in the Nuba Mountains as a way of galvanizing opposition to the evil of Sudan’s bombings.

One reason I’m so impressed by Dr. Tom is that most of the world, including world leaders and humanitarians, have pretty much abandoned the people of the Nuba Mountains. President Barack Obama and other global leaders have been too silent about the reign of terror here, too reluctant to pressure Sudan to ease it.

That’s the context in which Dr. Tom stands out for his principled commitment. Dr. Tom has worked in the Nuba Mountains for eight years, living in the hospital and remaining on call 24/7 (the only exception: when he’s unconscious with malaria, once a year or so).

Dr. Tom acknowledges missing pretzels and ice cream, and, more seriously, a family. He parted from his serious girlfriend when he moved to Africa, and this is not the best place to date (although hospital staff members are plotting to introduce him to eligible Nuban women as a strategy to keep him from ever leaving).

For his risks and sacrifices, Dr. Tom earns $350 a month — with no retirement plan or regular health insurance. (For those who want to support his work, I’ve posted how to help on my blog.)

He is driven, he says, by his Catholic faith. “I’ve been given benefits from the day I was born,” he says. “A loving family. A great education. So I see it as an obligation, as a Christian and as a human being, to help.”

There also are many, many secular aid workers doing heroic work. But the people I’ve encountered over the years in the most impossible places — like Nuba, where anyone reasonable has fled — are disproportionately unreasonable because of their faith.

I’ve often criticized the Vatican’s hostility to condoms, even as a tool to fight AIDS, and we shouldn’t tolerate religious bigotry against gays (which the latest Supreme Court ruling may chip away at). But we also shouldn’t tolerate another kind of narrow-mindedness: irreligious bigotry against people of faith. Diversity is a virtue, in faith as well as race.

Certainly the Nubans (who include Muslims and Christians alike) seem to revere Dr. Tom.

“People in the Nuba Mountains will never forget his name,” said Lt. Col. Aburass Albino Kuku of the rebel military force. “People are praying that he never dies.”

A Muslim paramount chief named Hussein Nalukuri Cuppi offered an even more unusual tribute.

“He’s Jesus Christ,” he said.

Er, pardon?

The chief explained that Jesus healed the sick, made the blind see, and helped the lame walk — and that is what Dr. Tom does every day.

You needn’t be a conservative Catholic or evangelical Christian to celebrate that kind of selflessness. Just human.

Nicholas Kristof is an Op-Ed columnist for The New York Times.