Can religion foster social justice or should it be perceived as a necessary conservative or heteronomous institution? Religious beliefs and practices are crucial factors influencing people’s relationship to the social world and to the political game. This chapter examines Dolores Mission Church’s struggle for social justice in Los Angeles, USA. From a sociological point of view, the study of the social and political consequences of religious practices in terms of the dynamics of mobilisation and politicisation shows that religion is far from marginal. Numerous historical works study the role of the Church in socialising the democratic order. This chapter focuses less on the analysis of the (in)justice frames of the movement than on the way this shared goal breeds the mobilisation of church members in struggles for social justice and is diffused along the participation to religious ceremonies. How can social justice be promoted by members of the working class rather than by benevolent middle classes? This is the aim of the community organizing tradition studied, showing how the church has constituted itself as a space of solidarity in the face of the anomy that dominates American working-class neighbourhoods, marked by the withdrawal of the state, mass unemployment and a high level of criminality.