To many people, Rahner's theology is somewhat enigmatic. They know on the one hand that it has inspired some of the most profound and responsive Christian pastoral action and spiritual insight in the twentieth century. At the same time, his writings, which he himself acknowledged to be mostly unschematic ("investigations" or "explorations" for the most part) seem inaccessible and bogged down in endless qualifications and philosophical constructs. This book takes the reader as its starting point and sets out to present the essential contribution of Karl Rahner to our lived understanding of Christianity. The first part of the book will attempt to contextalise Rahner both in terms of personal and of theological influences; this on the basis that all good theology is to some extent autobiographical, and that understanding the person is important to understanding his work. It will also summarise and present what Rahner has to say about living fully as human beings. This (second) chapter will help the reader to appreciate why working through the rest of the book will be worthwhile. The core of the book will be the three chapters on God, Christ and Church. In these contexts, key concepts will be elaborated, for instance, Rahner's understanding of the theology of symbol, his nature/grace, the trinity etc. The final part of the book shows Rahner's enduring place in the history of Christian theology by elaborating the fruits of his work in pastoral and spiritual terms, and by taking seriously criticisms of his work from such diverse perspectives as Political or Liberation theology on the one hand and Hans Urs Von Balthasar on the other.