Despite a provocative title, Gabriel Vahanian's book "The Death of God" caused no public stir when it was published in 1961. By the middle of the decade, however, a massive upheaval was underway in American society and Vahanian, a little-known Syracuse University professor of religion, found himself at the center of a furious national debate. The French-born academic entered the spotlight in 1965 when Time magazine's Easter week cover posed the question that Vahanian and other radical theologians had raised: "Is God Dead?" The arguments pro and con were still churning more than a year later, when the magazine noted...