Santana and Saul tells the story of a long-time friendship between two men who lived completely different lives and hold different religious beliefs.

The "dual memoir," as the author Saul Diskin calls it, tells the story of Santana, a guy who spent 30 years in and out of prison, was addicted to heroin and influenced by the the gangs, drugs and violence on the streets of southern California.

Diskin met Santana in a California prison, where Diskin was an undercover investigator. There, the two became friends as young men, but later separated when Diskin moved to Arizona to be a farmer.

In 2005, 48 years after they'd met, Santana contacted Saul and the men rekindled their old friendship. By then, Santana had been out of jail and completely turned his life around. After hearing that Santana was a husband, father and devoted preacher, Diskin said he had to go visit Santana to see such an unbelievable change.

But Diskin said the book doesn't just tell the story of Santana and the two men's friendship, it also shows a relationship between two completely different people with a different set of beliefs.

"People of different backgrounds, different classes, different intellectual interests can be friends without having to want to persuade the other one to his point of view," Diskin said. "I remain a non-believer, he remains a committed Christian but we still have great affection for each other."

Diskin is not religious at all, so when Santana called and asked him to write a memoir about his (Santana's) life, Diskin was hesitant at first. Santana had recently read Diskin's first book, a memoir about how his twin brother died, before contacting Diskin with the idea of a book about how faith and the church completely changed him.

Diskin finally wrote the dual memoir, 75 percent of it being about Santana. In order to write it, he had to spend hours shadowing Santana, learning about his life and taking notes. After sending it to multiple publishing companies known for religious writing, and being turned down by all of them, Diskin decided to self-pubish the memoir.

"There wasn't enough religion in it," Diskin said. "A great deal of the book had to do with his life as a criminal because it's the Christian story. You know .... they say 'hate the sin, love the sinner' ... but what they really wanted was for that market was all redemption and no sin and ... that would've been impossible to put my name to something like that."

Santana and Saul: A Dual Memoir was published by Author House, a self-publishing company, and can be ordered at any bookstore. The hardcover costs $29 and paperback costs $20. Both are available on Amazon and at Barnes and Noble. The eBook version costs about $4.