The evangelical embrace of conservatism is a familiar feature of the contemporary political landscape. What's less well-known, however, is that the connection predates the Reagan revolution, going all the way back to the Depression and World War II. Evangelical businessmen at the time were quite active in opposing the New Deal--on both theological and economic grounds--and in doing so claimed a place alongside other conservatives in the public sphere. Like previous generations of devout laymen, they self-consciously merged their religious and business lives, financing and organizing...