In an outbreak of violence in early December, screaming rioters in a Nairobi slum worked their way along sewage ditches, destroying anything in their way.

Angry youths looted and set homes ablaze. Caught up in the destruction, Joshua N. Gatoto fought his way through the crowd while protecting his eyes from tear gas.

Gatoto's search for refuge ended at a mud-brick church set off the main path through the Nairobi slum known as Kibera. Gatoto expected to find many Christians bowing in prayer. Instead, he found others like himself—lost and in search of peace.

"The Christians—they left with everyone else when the trouble started," Gatoto says. "The Christians may have left Kibera, but God did not leave."

Officials say tensions between landowners and tenants sparked the rioting. Kibera, the second-largest slum in Africa, rests on a 300-acre plot and is home to several hundred thousand people. Fifteen people died, hundreds were injured, and many women were raped during the weeklong riot. Rioters burned and chopped apart homes.

A strong Christian community and crushing poverty are no strangers to Kenya. The country of 30 million people is 78 percent Christian and 36 percent evangelical, according to Operation World. The annual income per person averages only $340. Slums such as Kibera provide churches with ministry opportunities.

As the violence spread through the slum, however, many Christian organizations and projects shut their doors, locking out rioters as well as people seeking refuge. Eyewitnesses say police in some instances only made matters worse. Kibera residents accused police of trying to portray the riots as part of a religious dispute between Christians and Muslims. But groups of Kibera men guarded mosques as well as churches ...