This new collection of essays by West Germany's most distinguished Roman Catholic theologian covers the two broad areas indicated in the title. The first half discusses the Christian understanding of God; the place of Christianity in the modern world; the modern sense of freedom and history and the theological definition of human rights; christology and anthropology; and the possibilities of a new spiritual christology in a trinitarian setting. The second half discusses various aspects of the church: as universal sacrament of salvation; as the place of truth and as communion. Two final studies examine the continuing challenge of the Second Vatican Council and the fundamental form and meaning of the eucharist. An extended introduction considers systematic theology today and the tasks which confront it.