What does it mean for an historically colonial church to become the “church of the poor” in a world marked by pervasive and persistent coloniality? Re-membering the Reign of God addresses this question through historical and theological reflection on the decolonial evolution of El Salvador’s ecclesial base communities (CEBs) in their own particular context of coloniality and prophetic hope. The CEBs’ witness represents a rich locus for decolonizing theology and challenging the whole church to join the church of the poor in its prophetic praxis of decolonial solidarity.