Sexuality is both fascinating and troubling. It seems to promise that transcendence of ourselves which is our deepest human desire, and yet it makes us painfully aware of our limits and of the supreme difficulty of finding ourselves in the process of losing ourselves. The relationship of Christianity to sexuality has been particularly troubled, but this book is an attempt to reflect on the phenomenon of sexuality from the standpoint of what is central to Christianity, that is, the view of God and of the human condition which became real in the words and in the life of Jesus of Nazareth. The book tries to answer this question: if we take Christianity seriously, how do we think about our sexuality and what do we do about it? This book draws on the ethical reflections of many thinkers, and it draws on much work in psychology, but its primary focus is either that of ethics or of psychology. The book intends to be theology: the attempt to talk intelligently about God and the relationship of God to every area of human existence and especially to those aspects of life which are near the center of the human personality: and foremost among such is sexuality.