Nigeria’s 150 million people are almost evenly divided between Christians and Muslims. And for several decades, fighting has repeatedly flared between the two groups, killing an estimated 20,000 people. But two men, once sworn enemies, are now working to undo the hatred they once sowed.Nigeria’s 150 million people are almost evenly divided between Christians and Muslims. And for several decades, fighting has repeatedly flared between the two groups, killing an estimated 20,000 people. But two men, once sworn enemies, are now working to undo the hatred they once sowed.