The Louisiana State Penitentiary, known as Angola, is the largest prison in the United States. Louisiana's most-hardened inmates end up at Angola. Most will die there. Angola is home to the state's death row and the most restrictive cell blocks. It's also where every man serving a life sentence in the state waits out his days. In Louisiana, life means life. No parole. No reduction of sentence. Nothing short of a pardon—or death—will release a lifer.

Until the 1970s inmates served as guards, and killing an escaping prisoner could earn one a ticket home. Prisoner-on-prisoner violence was common. Men slept with layers of newspapers and magazines under their shirts as rudimentary protection against nocturnal assaults with shivs, prison-made knives. An inmate's lawsuit in the mid-1970s forced reforms that ended much of the brutality.

Welcoming God into the prison has made even deeper changes for the 5,100 men locked up there. The faith-based programs that Warden Burl Cain has encouraged have led to genuine repentance—and to prisoners graduating from seminary and going as missionaries to other prisons. That is unique in a country of 1,850 prisons.

The beauty of the prison's 18,000 acres belies more than a century of misery soaked into the fertile soil.

"This land has had more human suffering than any land in America from its beginning as a slave-breeding plantation," Cain says. After the Civil War, he notes, forms of slavery continued until 1901, when the state took over the prison. Angola spent a century building its reputation as the most dangerous prison in the country.

Ron Humphrey, a senior writer for Chuck Colson's Prison Fellowship, says inmate-on-inmate murders sometimes numbered a ...