The nineteenth century’s “social purity” campaign against prostitution highlights the role of Christian theology in empowering women in social activism. This paper will tell the story of the nineteenth-century social purity movement by drawing on what has been called “Globalizing Historiography”: telling the story of five social purity movements in four countries during the years 1870-1910, spanning from Great Britain and the United States to Scandinavia and Japan. Examining these interrelated movements as a global phenomenon yields the conclusion that social purity was a woman’s movement that drew on Christian rhetoric and theological categories to advance women’s interests and confront male sexual immorality. As Black, white, and Asian women read their Bibles, they translated outrage into social advocacy, and thereby turned moral influence into social power.