After Grant Wacker finished working on his seminal study of American Pentecostalism, Heaven Below: Early Pentecostals and American Culture (2003)--or “after it finished working on me,” he says--Wacker cast about for another big topic. His friend, fellow historian Mark Noll, suggested he consider writing a biography of Billy Graham. That intrigued Wacker, professor of Christian history at Duke Divinity School in Durham, N.C., but he wanted to do more than write the story of the evangelist’s life. “After all,” he says, “Graham has written two autobiographies.” Instead, Wacker tackled the larger task of analyzing and assessing Graham’s impact on American culture. The result is America’s Pastor: Billy Graham and the Shaping of a Nation (Harvard, Nov.).

Wacker feels he’s always known Billy Graham. “I grew up in the evangelical tradition, and my parents took me to a Billy Graham Crusade when I was very young,” he says. By the time he was in graduate school, Wacker had enough distance from his religious upbringing to question some of Graham’s public decisions. He even wrote a letter to Christianity Today to point out how Graham lost credibility because of his relationship with Richard Nixon. Then, starting in 2007 and over the next four years, Wacker got the chance to meet Graham, visiting him several times at his home in Montreat, N.C. Face to face with the evangelist, Wacker felt Graham’s elusive charisma and deep humility. “I had the sense of being in the presence of someone who is extraordinary,” he says.

In America’s Pastor, Wacker explores the many ways Graham shaped the American conscience during the latter half of the 20th century. “What attracted me to Graham is his ability to elicit such deep devotion and, often, harsh criticism at the same time, and the ways the devotion [for him] far outweighs the criticism.” Graham has affected so many people, Wacker believes, because he is a complex, multi-faceted figure who appeals to many segments of society; people see in Graham whatever part of him touches them most. When people wrote letters to Graham during his active ministry, Wacker says, they wrote openly about their grief, fears, and joys--they found in him a way to rebuild their lives, and those letters provide a telling index of the state of American society at the time.

Wacker says Americans have responded to Graham because he preached the possibility of personal transformation, the gospel of a second chance. Graham’s legacy can be seen in his influence on many people, among them his son and heir apparent, Franklin, who represents his father’s more conservative side, as well as the influential pastor Rick Warren (The Purpose Driven Life), who captures Graham’s more moderate message. Graham’s style of evangelical Christianity--inclusive, irenic, politically progressive--and his life-affirming way of framing faith are uniquely his own. Notes Wacker, “I don’t ever think we’ll see another Billy Graham.”