For many believers today the doctrines of Atonement, Christology and the Trinity seem like puzzling constructions produced by academic theologians. They are cast in unintelligible forms of thought derived from Platonism or from feudal society, and for many their existential relevance for life today remains unclear.This book introduces these doctrines and proposes a reinterpretation in the light of the claim of many Christian mystics that ultimate happiness is to be found in enjoying the loving fellowship of God. This claim is a matrix of faith in terms of which these doctrines are shown to be relevant for the life of faith of believers today. Furthermore, since this matrix can be defended within all three Abrahamic traditions, Judaism, Christianity and Islam, the proposed understanding of these doctrines can also contribute usefully to the necessary dialogue between these traditions in a globalised world.