This book represents a comprehensive and thorough study of the theology of religion of Gustav Warneck, Hendrik Kraemer, and J.E. Lesslie Newbigin. The author provides general bibliographical information on the three men (all of them important writers in their own right), as well as an overview of each one's mission theology. The main emphasis, however, is on the theology of religion of each of the three main subjects. The author chose to focus on them because they all show a clear preference for an exclusive view of Christianity, although each one has a unique approach to theology. Griffioen has consulted the main texts produced by the three theologians, and his descriptions of their individual encounters with other scholars (to establish how they relate to other theologians) are most enlightening.