How does one become a "Righteous among the Nations"? In the case of Henri Nick (1868-1954) and André Trocmé (1901-1971), two French Protestant pastors on whom that title was conferred by Yad Vashem (Jerusalem) for their acts of solidarity toward persecuted Jews, the answer seems to be: by being immersed, from an early age, in the discourses and practices of social Christianity. By focusing on the lives of two significant figures of twentieth-century Christianity, this study, the first in English on the Social Gospel in French Protestantism, presents a genealogy of that movement, from its emergence in the last decades of the nineteenth century to its high point, during World War II, in Le Chambon-sur-Lignon, where Trocmé and many people of that area of southern France rescued hundreds of Jewish refugees. As social Christians who prayed and worked for the coming of God's kingdom on earth in the midst of a world torn by two world wars, Henri Nick and André Trocmé combined a deep revivalist faith with a concern for the concrete conditions in which people live. They wished to "save" others, and indeed they realized that intent in ways they did not foresee.