Given the chance to survey evangelicalism's growth and development through the twentieth century, Steve Rabey and Monte Unger did what any of us might have done. In preparing their new book, Milestones: 50 Events of the 20th Century that Shaped Evangelicals in America (Broadman and Holman), Rabey and Unger spent over 50 percent of their time looking at the '50s, '60s, and '70s—over 40 percent in the latter two decades alone.

It seems clear from this book that the middle decades were, indeed, where the action was really at in 20th-century evangelicalism. From Billy Graham and the rise of mass evangelism in the 1950s to the ascension of evangelicals like Colson and Carter to political power in the 1970s, the movement again and again asserted itself—and reinvented itself—across many cultural arenas.

Don't get me wrong. This is no exercise in antiquarianism. Out of their historical material the authors have built an up-to-the-minute composite portrait of the movement. Their avowed guiding question was "What things, for better or worse, have had the greatest impact on making evangelicals who they are today?"

In choosing to survey the century just ended, Rabey and Unger do fall heir to the peculiar difficulties of doing near-contemporary history: When we look back over a period mere decades past, it's often hard to sort out the trivial from the lasting.

But when we hit the twentieth century's middle years, the time lag seems about right. In some of their best short chapters (none is longer than the average magazine article) the authors, now at some distance from the initial hype, are able to do helpful analysis and fruit-testing of such vintage but still-powerful trends as the church growth movement and seeker-sensitive ecclesiology.

Another advantage of the book's focus on the middle decades is that this is truly unknown territory for many readers who came to the movement either relatively late in their lives (I fit that category, having converted in 1984 at age 21) or late in the movement (anyone who's a teenager or young adult now). It's always instructive to see what put a fire in the bones of those whose legacy we enjoy (or suffer).

On the other hand, some of this material may just make some of us feel old. I certainly found myself asking at several points in the book: Has such-and-such been around that long? It can't possibly have been that many years since Amy Grant ushered Christian contemporary music into the mainstream (1985, chap. 40), Willow Creek spurred the megachurch movement (1975, chap. 34), the NIV challenged the KJV's traditional dominance (1973, chap. 32), or James Dobson launched his family-values crusade (1970, chap. 28). Excuse me while I get my Geritol.

At other points, readers may find themselves asking another, similar question: Are we still fighting those same battles? Given how much of what we are now—good, bad, and questionable—was launched in those short decades at the middle of the century, the feeling of dé;jà; vu suffuses the chapters on the clash of evangelical morality and sexual freedom (1953 and 1973, chaps. 16 and 31), the wrangles over religion in the classroom (1962, chap. 21), and the growing popular taste for esoteric spirituality (1968, chap. 26). Are evangelicals stuck in a cycle, rehashing old concerns whose ground rules and strategies were laid out long ago?

Yet the authors never let history sit. Each chapter moves from the events of the past to the trends and concerns of the present. So in chapter 22 on Martin Luther King Jr. and the civil rights movement, the authors update King's concern that Sunday morning from 11 to 12 is America's most segregated hour, with the telling fact that although by 2001 nearly half the U.S.'s big cities housed more minorities than whites, evangelical churches remained among the nation's most segregated. And in the chapter on the experimentation with non-Western religions in the sixties (chap. 26), we are reminded that continued immigration to America from Asia and the Middle East has today broken the old Protestant-Catholic-Jewish monopoly, as by the late 1990s Muslims outnumbered Episcopalians in the U.S.

Though Rabey and Unger demur from offering a grand summary at the end, a core picture of evangelicalism does emerge. We see a movement marked first, by its evangelistic activism, and second, by this activism's twin (sometimes, the authors imply, its evil twin): a chameleon-like skill in adapting to cultural trends in order to spread the gospel.

Both of these powerful forces drove major changes in the movement's identity during the '60s and '70s, so it is no surprise to find their epitome in 1970. That year saw the release of D. James Kennedy's famed manual, Evangelism Explosion. The authors editorialize that though the book has helped thousands of evangelicals reach millions with the gospel, "the program exhibits problems that have bedeviled many of the mass evangelism campaigns that became increasingly popular during the 1960s and 1970s: it converted Christianity into a commodity and marketed it like any other consumer product, emphasizing its immediate benefits and downplaying its long-term costs." Rabey and Unger link this commodification to Bill Bright's "Four Spiritual Laws" tract, which they call "the most widely distributed document in evangelical history."

Other, much more positive benefits have accrued from this evangelical penchant for culturally strategic "gospel activism." One is the movement's (improving) record of cooperation both within its boundaries (chap. 8 on the National Association of Evangelicals, chap. 18 on the founding of Christianity Today) and without (chap. 45 on recent efforts to find common ground with Roman Catholics). Another is the sheer creativity and multiplicity of the ways evangelicals have "done church" (chap. 1 on the founding of Pentecostalism, chap. 20 on the charismatic movement, chap. 27 on the Jesus People, chap. 48 on "postmodern" modes of ministry to "Generation X").

In the end, evangelical readers of this account needn't always like what we see. In fact, we should be suspicious if we do. But unless we know our genealogy—the peculiar mix of theological nature and cultural nurture that make us who we are—we are doomed to do the things we do in darkness. This book ushers evangelicals towards the bright exit of that tunnel of history-blindness.

Chris Armstrong is managing editor of Christian History magazine.