When the editors of Relevant, a magazine for Evangelical hipsters, spun off a series of spiritual biographies of musicians a few years ago, they went straight for the most problematic Christians they could find: Bob Dylan, whose dalliance with Jesus in the 1970s was hot, heavy, and apparently short-lived; the Irish rock group U2, whose lead singer Bono flirts constantly with believing fans in his lyrics and coy statements about his faith (“I’m a fan, but I’m not in the band”); and Johnny Cash, who made no bones about his allegiance to Christ yet identified with sinners to the point of glorifying sin in his songs.

With their nubbly covers and chunky, sparsely printed pages, Relevant’s quickie bios were reminiscent of those pop-psych-for-teens books you used to find in church narthexes in the ’70s, and they had similar aims: to nudge readers toward Christ by showing them that Christians can swim in the currents of ambiguity, alienation, and experimentalism of modern American adolescent culture.

When I first spotted Rodney Clapp’s new book, Johnny Cash and the Great American Contradiction: Christianity and the Battle for the Soul of a Nation, it looked to me like a similar exercise, albeit for adults. Clapp, editorial director of the Christian publishing house Brazos Press, has a reputation for intellectual irreverence—throwing Elvis Presley into an Augustinian argument about sex, or using Bambi to tease out a point in Leviticus. But Clapp is a confirmed Evangelical, and Brazos is dedicated to writings that are “distinctly, particularly, and unashamedly Christian,” according to its mission statement. I had no doubt that, in Clapp’s hands, the figure of Johnny Cash, writ against the backdrop of our national life, would be portrayed as a flawed but faithful Moses who nonetheless could lead us to the promised land.

I was right—though hardly in the way I suspected. In this satisfying yet querulous book, which contains an accounting of public-domain acreage granted to U.S. railroad companies in the nineteenth century, a blow-by-blow analysis of a 1964 Jerry Lee Lewis performance in Germany, a catalog of Hank Williams’s “primal and needy” vocalizations in “I’m So Lonesome I Could Cry,” and a brief history of America’s failure as global cop, Cash makes only occasional appearances. Clapp treats his subject less as a man than as a sort of hologram in whose image we can fuzzily glimpse the contradictory impulses of the American Experiment: rugged individuality versus community, patriotism versus dissent, piety versus materialism, nostalgia versus progress, peace versus war. By embodying these warring values, Cash is “quintessentially American,” Clapp says.

The good news from Clapp is that Cash often comes down on the side of good theology. As a country musician, Cash bemoaned, with Hank, the loneliness that could kill—score one for the Christian concept of “creatureliness,” or dependence on God and one another. The singer of the “Folsom Prison Blues” and “Down There by the Train” reached out to prisoners, Native Americans, even Judas Iscariot and John Wilkes Booth—score one for redemptive grace.

And yet the book is not “What Would Johnny Do?” In some instances, Cash only holds the two contradictory impulses in tension, offering no clear moral choice. Here Clapp takes over, disentangling the contradiction by separating what we practice from what we preach. He picks apart our frontier ideal of individualism, citing how often and how substantially the U.S. government has fostered development in places that today are antigovernment strongholds, like Arizona, Georgia, and Colorado. He ridicules our self-regard as a shining city on a hill, criticizing the picture of “America as the Savior Angel of humanity” as “but the mirror image of the equally incredible designation of America as the Great Satan.” Doling out negligible homicide statistics from Dodge City, Deadwood, and Tombstone, Clapp waves away romantic notions that the United States was founded on lawless violence (born of necessity) that might justify our international gunslinging today.

It won’t escape notice that Clapp’s criticisms are leveled mostly at values close to the heart of recent Republican administrations. Though Clapp writes of Cash that “his Americanism is too broad and too deep to stand on only one side of our current red state vs. blue state divide,” the book appears to be aimed at shaking up fellow Evangelicals who have gone red in great numbers over the past few elections. Clapp is among those Evangelicals who regret how deeply intertwined devout Christians have become with the aims of conservative Republicanism, but unlike other Evangelicals who share his qualms, he doesn’t see the partnership as a mere accident of politics.

For Clapp, the destructive delusions of moral superiority spring from the religious tradition of the tent meeting. Over the past forty-five years, the center of our political culture has shifted southward. A democratic system founded by a farmer elite and taken over by the urban mob, or what Clapp calls the democracy of the parade, has come to be characterized by the signal religious experience of the South, the revival. With their focus on saving individual souls, revivals nurtured individualism to the point of solipsism. Clapp repeatedly recalls an 1801 revival in Cane Ridge, Kentucky, where enthusiasts bayed like dogs. “Each soul may have communed with God,” he writes, “but they hardly communicated with each other.”

At the same time, revivalism leaves Christians “wary of individual differences,” he says. “People are reconciled not so much to the God of the Bible and Christian history as they are bound to social conventions.” Combined with the South’s view of itself as “the last redoubt of Christianity in the civilized world,” this religious ethos fostered, far more than any political alliance could, a democratic style that confuses local custom with basic Christian tenets, while demanding a role for the church in the larger public square.

As hard as he is on his Evangelical brethren, Clapp’s caution to the rest of us is worth noting. Blue-staters as far back as Robert Kennedy have accused the Christian movement of using piety to gain power. (In a more recent example, Barack Obama opined during the Democratic primaries that certain classes of folks cling to religion out of “bitterness” when times get hard.) Clapp reminds us that “the Southern-accented Christian faith of millions of Americans is real and primary.”

The question for Clapp is how these true believers should take part in our diverse national life. Christian citizens on both sides, red and blue, could do worse than take heed of the man who came around, who “tithed” one gospel song for every hard-livin’ country tune. A few years before he died, Johnny Cash told Rolling Stone, “There’s nothing hypocritical about it. There is a spiritual side to me that goes real deep, but I confess right up front that I’m the biggest sinner of them all.”