Christianity is often assumed to be pro-capitalist and socially conservative - in short, necessarily aligned with the political Right. But can this be straightforwardly true of a religion founded by a figure who drew his early followers from among the poor and downtrodden and spoke against the accumulation of earthly riches? In this book, Anthony A.J. Williams shows that this assumption is far from correct by giving an introductory overview of a tradition of socialist and radical Christianity that can be traced back to the communal ownership described in the Acts of the Apostles. Focusing on modern Christian Left movements, from Christian Socialism and the social gospel to liberation theology and red-letter Christianity, Williams examines the major challenges faced by the Christian Left today, both from within Christianity itself and from the secular Left. Does the Bible and Christian theology really support collectivism and universal equality? Can Christian radicalism remain viable in an age of identity politics? This book is essential reading for anyone interested in the relationship between religion and politics.