In the Nigerian town of Kaduna, two religious men were out to kill each other. And they almost did.

But now Pastor James Wuye and the Imam Muhammad Ashafa work side by side trying to heal the divide between Nigeria’s Christians and Muslims. They are the heads of the Interfaith Mediation Centre, which is housed in a brick building here in Kaduna along the frontline that straddles the Muslim neighborhoods to the north and the Christian neighborhoods to the south.

Once mortal enemies, the Christian pastor and the Muslim imam emerged in Kaduna in the 1990s, when they both served as religious fundamentalist street leaders who trained local militias to intimidate and kill the other side at a time when the religious conflict was first heating up. They lost a great deal in the process. Pastor James lost his right hand and many friends. Imam Ashafa lost family members and a beloved mentor.

In long interviews with Pastor James and the Imam Ashafa, they described those years of battle and the deep hatreds, the long history and petty grievances that fueled them. They confessed that they were often targeting each other for death. They also described their own separate processes of spiritual transformation that led them to renounce violence and to find a way to begin to work toward reconciliation with the other side.

The young men and boys whom they once trained to kill, they now work to “deprogram” from the hatreds they have learned. They are now famous in Nigeria and are popularly known quite simply as “the pastor and the imam.” They have a television talk show and make frequent international appearances to tell their story.

“To me, they are two brothers,” said Kaduna’s Governor Ramalan Yero.

“These two gentleman are working to ensure peace between Christians and Muslims not only in Kaduna and in Nigeria, but across the African continent. We see no reason why we cannot emulate these two gentlemen, and unite ourselves and have the same courage and wisdom they have in doing what they are doing,” the governor added.

The pastor and the imam’s joint efforts recently culminated in an international peace conference over which the governor presided. They served as hosts of the fourth annual International Forum for Cities in Transition which wass organized by the University of Massachusetts-Boston at the end of November. It was a six-day conference that brought together some 50 delegates from divided cities in Lebanon, Kosovo, Bosnia, Iraq, Northern Ireland, Israel-Palestine and elsewhere.

The delegates came with practical lessons they’ve learned in helping their own cities reach out across sectarian and religious divides to find workable systems of governance, policing and education. The core idea, which was developed in the life-long work of author, activist and UMass professor Padraig O’Malley, is for these municipal leaders to meet and share their stories and to learn from each other.

Kaduna was chosen as the seat of the international gathering because, thanks in large part to the pastor and the imam, Kaduna has earned a reputation as a vanguard in efforts at reconciling the Christian and Muslim sides of the community.

But it wasn’t always that way.

Pastor James gestured with his artificial right hand as he remembered back to the darkest days of the 1990s when Kaduna was launching into a religious conflict. He spoke of orchestrating attacks by dispatching Christian youths specifically to attack Ashafa’s men. He remembered plotting to kill him. Instead, a Christian militia ended up killing several of the imam’s cousins and throwing the imam’s beloved mentor, a Sufi sheikh, down a well and burying the body with stones.

That image of violence and depravity was hard to square with the beautiful Sunday morning services at his church where families came together in their brightly colored Sunday best and swayed to the rocking sound of the gospel song, “What a Mighty God We Have.”

Sitting cross-legged on the green carpet inside the mosque where he now serves as imam, Ashafa stroked his grey beard and waited for the call to prayer to end. He stopped to pray and then returned to tell his side of that violent past. Specifically, he remembered a time in 1992 when he dispatched a gang of his young men to kill the pastor for what he had done to his family and mentor.

“I was full of vengeance. I decided I had to eliminate him, eliminate his group because they had committed an unforgivable sin,” remembered Imam Ashafa.

He remembered being disappointed, he said, when he found out the pastor survived, though the pastor did lose his right hand in the attack when it was severed by a machete.

But later in 1992, a sermon by a local imam started to change his heart, Imam Ashafa said. The sermon was about the Prophet Mohammed’s journey to Taif when the prophet said to the angel Gabriel, “My Lord, forgive my people; they do not know what they are doing.”

And the sermon went on to quote the Quran; chapter 41, verses 36 to 42, which Imam Ashafa summarized as, “Turn the evil to that which is good … No one will have the courage to do this except the people of perseverance … If you do that the worst of enemies will become the best of friends.”

“Then and there I became a free man,” Imam Ashafa said, explaining that soon after he went to Pastor James and visited him in the hospital where he was caring for his sick mother. He asked the pastor for forgiveness.

Pastor James was weary and remembered not trusting the sudden change of heart on the part of Imam Ashafa.

But then Pastor James began a transformation of his own in the mid1990s at a conference sponsored by the American Christian fundamentalist and televangelist Pat Robertson. Even though Robertson is one of the most virulently anti-Muslim preachers in the world, there was a fellow pastor at the conference who pulled Pastor James aside, saying “You can’t preach the gospel of Jesus with hatred in your heart.”

“That was my turning point, that was when I was changed and when I really opened up to the idea of forgiveness and of trying to work together to stop the killing,” said Pastor James.

But it took a further three years, until 1998, before he said he could genuinely feel a sense of forgiveness for Imam Ashafa.

Eventually, the two men began working together. And in the 15 years since, then have formed an intense relationship, a deep friendship and a productive partnership through the Interfaith Mediation Centre. They often joke that they are like an old, married couple now.

“Not everything goes smoothly between husband and wife, there are moments of tension,” explained Imam Ashafa.

“But what keeps us going is a spiritual commitment to God, that we want to make the world a better place,” he added.

The imam said, “I am not a Christian and I don't want to be a Christian. James is not a Muslim and he doesn't want to be a Muslim. But understanding that religion is about building bridges, that article of faith, that principle in the Abrahamic tradition, is what keeps us going.”

This story by Charles M. Sennott is from a special report published by our partner GlobalPost. It is part of The GroundTruth Project and was supported by a grant from the Henry Luce Foundation for reporting on religion.