iolence is a constant in Karachi, Pakistan's troubled commercial capital. More than 600 people have been killed in ethnic and gang warfare in the past six months. For Abdul Sattar Edhi, Pakistan's best-known humanitarian, easing the city's agony is a matter of business as usual. The white-bearded charity worker is a familiar presence at disaster scenes, rushing the injured to hospitals in his ambulances and washing or burying corpses. Even the most hardened of killers take special care to protect Edhi. An armed thug once pushed him to the ground to spare him from the crossfire--and collapsed dead on top of him moments later. "My case is a miracle of God," says Edhi.

　　In his native Gujarati language, Edhi's family name means "lazy," but in 45 years of charity work, he has never taken a holiday. With only an eighth grade education, Edhi shoulders the social work in Karachi that the government should be doing but fails to do. A young immigrant to Pakistan after India's partition, he abandoned a cloth-selling business to start a clinic after the death of his mother, whom he cared for during an eight-year illness. Shortly afterward, he began a one-man ambulance squad. That service has grown into the largest and best-run social welfare system in Pakistan. Edhi refuses government aid, relying instead on private donations that total about $5 million a year. Known for his humble, forthright style, he wears a simple gray shalwar-kameez, Pakistan's traditional dress, and lives in two rooms above his foundation's office with his wife Bilqis, a volunteer nurse he met in 1965. "The others are pygmies compared to a man like Edhi," says Tehmina Durrani, a Lahore writer who compiled the illiterate humanitarian's 1996 autobiography, A Mirror to the Blind. "He is the only man who has done good governance in Pakistan."

　　Because of rampant political and ethnic strife, Karachi no longer has a mayor or city council but is run by some 35 agencies known for their corruption and lack of coordination. As a result, municipal administration is a shambles. People have come to rely on Edhi not only for his 24-hour emergency services--he has 70 ambulances in Karachi and 450 total, as well as a helicopter and two planes for medical airlifts--but also for his homeless shelters, orphanages, blood banks and homes for unwanted infants. "Don't kill," say the simple hand-lettered signs above the blue cradles stationed outside Edhi's centers. "Leave the baby alive in the cradle. Do not kill the baby. "More than 22,000 infants--who often arrive with tags designating their religion--have been saved by Edhi and Bilqis, who works alongside her husband.

　　For older kids there are orphanages, where Edhi is revered as everybody's father. He visits the homes each week. At one outside Karachi, 250 boys with shaved heads stand eagerly in line awaiting his handshake. "Baba [father] has come!" they shout. Edhi hopes the children will carry on his work when they grow up. "This batch will one day be my missionaries," he enthuses.

　　Although the 69-year-old Edhi is often compared to Mother Teresa, the resemblance ends after their remarkable devotion to charity. Unlike the late Calcutta-based nun, Edhi eschews publicity. And while she enjoyed the support of the Catholic Church, he has tangled repeatedly with his fellow Muslims. He sees charity as a fundamental priority of Islam but criticizes Muslims for not believing strongly enough in it. His detractors--mostly hardline Islamists--have issued death threats against him and his family, condemned his egalitarian treatment of women as un-Islamic and accused him of encouraging out-of-wedlock births through his baby cradles and orphanages. Late last year, members of a right-wing Islamist group stormed one of his Karachi hospitals and still occupy it. "Early on the criticism horrified me and left me depressed," he says. Nowadays, the threats and obstacles bother him less. He is satisfied that he has put together a durable system that will last long after his death. Says Karachi's humanitarian: "My life is complete, so what is there to worry about?"

　　Indeed, Edhi never lets hardship get in the way of his work. Over the years, his ambulances have been set on fire and volunteers have been killed in attacks. "But even then we did not stop work," he says. The greatest tragedy of all was a personal one. Edhi's favorite four-year-old grandchild died of burns received at the hands of an emotionally disturbed woman in one of his homeless shelters. Edhi was devastated by the boy's death, and friends say he withdrew emotionally after that--though he never wavered in his efforts to help the needy or in his calls for a Pakistani welfare state.

　　In a country bereft of modern-day heroes and known to the rest of the world for terrorism, drug-running and nuclear machismo, Edhi has become a singular voice of compassion. "He is the only beacon showing that there is still good in people," says Islamabad anthropologist Adam Nayyar. Sitting on the steps outside one of his homeless shelters for the handicapped near Karachi, Edhi surveys the green landscape with satisfaction. When he bought the 26 hectares of land almost a decade ago, there were no trees or water. He recently installed electricity generators. "At night all over, there is darkness," he says. "But here, there is light."

Photograph by Robert Nickelsberg for TIME