CHAPEL HILL, N.C. (RNS) For believers, he is the trustworthy messenger of God, a living link to the divine whose life and teachings animate the lives of an estimated 1.5 billion Muslims around the world.

Yet for detractors, Islam’s Prophet Muhammad is a polygamist who spawned a religion that subjugates women, condones violence, and was, in the words of Pope Benedict XVI, “spread by the sword.”

In short, when his best-known modern portrait is a 2005 Danish cartoon that depicts a surly bearded man with a bomb hidden in his turban, Muhammad has an image problem.

“He’s been remade in the image of Osama bin Laden,” said Bruce Lawrence, who directs the Duke Islamic Studies Center at Duke University. “People connect the dots and see this fanatical side of Islam and say (militants) must be following someone, and they point to Muhammad.”

Enter Omid Safi, an up-and-coming scholar of Islam at the University of North Carolina at Chapel Hill whose new biography, “Memories of Muhammad: Why the Prophet Matters,” attempts to discover the true Muhammad obscured by both hagiography and militant extremism.

“I’m trying to help non-Muslims learn things about Muhammad that they’ve never known,” Safi said over a pot of Ethiopian coffee, “and help Muslims remember things they’ve forgotten.”

Born in Jacksonville, Fla., and raised in Iran, his family fled Tehran in 1985 and sought refuge in the U.S. Tucked into their two suitcases was an image of Muhammad that now hangs in Safi’s home.

Safi, 38, is on the front edge of a generation of scholars who, with one foot in both worlds, are trying to explain Islam and the West to each other. His new book, published by HarperOne, positions Safi as a three-way translator between Muhammad, his followers and legions of critics.

In many ways, the schizophrenic images of Muhammad are as old as Islam itself. His divine revelation of monotheism in 610 A.D. was greeted as heresy by his polytheistic neighbors. In a society that prized tribal loyalty, he preached a message of universal humanity. When given the chance for retribution, he offered amnesty.

Even among his followers, some see Muhammad as near divine, but others see him as a mere mortal, a kind of “UPS delivery man,” as Safi writes, who delivers the Quran, “obtain(s) a signature to ensure that the item has been received, and then depart(s), never to be seen again.”

The truth, Safi says, is not something in the middle, but more a mixture of the two.

“Show me your relationship to Muhammad, and I will show you what kind of Muslim you are,” he writes. The same principle applies for non-Muslims. Perceptions of Muhammad, he said, closely shape views of Islam.

Safi says it is impossible to understand Islam without first understanding its prophet. Born in 570 in Mecca, Muhammad was orphaned at a young age and became a trusted merchant. At the age of 25, he married his boss, Khadija, who was 15 years his senior. “Today we’d call her a cougar,” Safi joked.

A deeply spiritual man, Muhammad would often retreat to caves to meditate in solitude. On one visit, in 610, he received his first revelation and was so freaked out he nearly broke down. Only after receiving affirmation from his wife did Muhammad go public with his new teaching. She became his first follower.

Slowly, his teachings gained traction, but his followers were forced into exile. After battling his way back to Mecca in 632, he purged the sacred sanctuary of idols (while saving icons of Jesus and the Virgin Mary) and died three months later at the age of 62.

Within 100 years of his death, the realm of Islam was twice the size of the Roman Empire.

In his book, Safi devotes considerable time to the devotional tradition that rose up after Muhammad’s death. His life and teachings were the inspiration of volumes of flowery poetry and served as a roadmap for godly life.

“He completely kept himself away from three things: from arguments, pride and senseless utterances,” wrote his grandson, Hossein, in typically glowing tribute. The Quran calls him “a mercy for all the universe.”

Safi says the devotional tradition is key to understanding Islam, and it’s one that too many Muslims have forgotten, and non-Muslims have ignored.

“Muhammad was not just a man who delivered the Quran,” Safi said. “He lives the Quran, he embodies the Quran. … If you want to be a follower of Muhammad, a child of Muhammad, then you have to know him. You have to know his ethics, how he treated people.”

He also puts Muhammad’s life in the context of 7th-century Arabia, where polygamy was not only common, but encouraged. He notes that after Khadija’s death, Muhammad “could have had his pick of the youngest and prettiest virgins in town, but he marries older women, and that says something.”

The problem for Islam, and for Muhammad, is that his legacy has been overtaken by a violent fringe who look to Muhammad as a warrior-prophet that Safi says the prophet would not recognize.

Safi writes that if Muhammad’s own followers don’t take up the “qualities of mercy and justice that Muhammad so perfectly embodied,” they don’t deserve the name “Muslim.”

“There will always be the crazies, the zealots and the extremists,” he said. “You’ll also always have the saints, the illuminated ones who feel the presence of God. Then there’s the rest of us who can be swayed this way or that. This book is an appeal to those folks.”