The article analyses the religious basis of the different attitudes towards the modern welfare state and state social assistance systems in countries that have been influenced by different Christian denominations, especially Catholic, Lutheran and Reformed (Calvinist, Presbyterian) Christianity. The article looks at early forms of poor relief in Lutheran cities at the beginning of the Reformation and their theological basis in Martin Luther’s writings. The article then looks at the different ways in which social assistance to the poor was organised in areas under Reformed influence and in Catholic areas. The article shows that the Christian obligation to support the poor underpins modern social assistance, but that it has played out in very different ways in societies according to the relative predominance of Catholic, Lutheran and Reformed Protestant religious heritages, and that these patterns can be seen today in variations in social assistance and welfare-to-work policies in OECD countries. The article shows that reference to the social doctrines and poor relief systems of historically significant Christian denominations can help to answer a number of otherwise puzzling cross-national differences in poverty policy. These include different beliefs and attitudes within Christian denominations, such as their understanding of salvation, their concepts of work and non-work (begging), their understanding of state-church relations and their understanding of the state in general.