The purpose of this study is to examine the church-state relations in the United States from the perspective of the social welfare system. More precisely, we are questioning the way the conceptual foundations and practical activities of religious organizations influence the directions of social policy and shape the way of dealing with the poor. The first part of the text outlines the main features of religious life and social welfare system in America, while the second contains an analysis of the impact of basic moral and religious principles of the Reformed Protestantism and Roman Catholicism (the two most widespread religious traditions) and the ways in which religious organizations are taking part in the modern social welfare system in America.