Secularisation theories often fail to distinguish between, on the one hand, the justified differentiation of religion and politics and the separation of church and state, and, on the other hand, the uncritical contentions about the marginalisation and privatisation of religion. In response to J. Casanova’s interpretation of the disestablishment of Catholicism and his argument for a more active involvement of religion in civil society, this article revisits several models of thought with regards to the relationship between religion and politics (e.g., separation, fusion, status confessionis, Max Weber’s thesis in Politics as Vocation, civil religion,public theology, political theology, and mediation models such as Christian democracy and liberation theology). Taking into account the merits and weaknesses of each model, an argument is made for a complex approach of the participation of Christians in politics which moves beyond confining religion to merely the sphere of civil society.