At a time when critics are attacking intellectual weakness, theological decline, and worldliness among evangelical Christians, there are also rumors of revival. Tens of thousands of men attend rallies and rededicate their lives to Christ and recommit to their marriages. Students in Christian colleges line up to testify and confess their sins. In Toronto, a congregation nestled among airport hotels becomes a jet-age version of the frontier camp meetings, drawing its attendance not just from the next county, but from other continents. Are events like these the overture to another great awakening—or even just a small one?

Jonathan Edwards, the Puritan theologian who has been called the greatest mind produced by America, was also the greatest theologian of revival. When we talk about renewal in the contemporary church, Edwards's writings provide us with the best standards available to help us judge what is genuine, what is spurious, and what is a mixture waiting to be purified.

THE INTROVERTED EVANGELIST

Early in his pastoral career, Edwards had to grapple with what it would mean for his congregation to be revived. His church was solidly orthodox and had experienced several harvests of conversions under Edwards's grandfather, Solomon Stoddard. In the 1730s, however, the church's orthodoxy was merely "notional," as Puritans would say. Parishioners knew their catechism and could rattle off the elements of Christian faith, but few of them cared deeply about Christ. They were absorbed and fascinated by business and everyday life, and they gave little attention to God.

In 1734, Edwards preached "A Divine and Supernatural Light," advancing a new theory of religious semantics. Professing Christians who have had truth drilled into ...