It is impossible to love God and at the same time be dispassionate about the study of God. Deep devotion to Jesus and an all-consuming desire to see his glory ll the earth should fuel the passion of anyone who ventures to write about God and help illuminate other people's understanding of God and his ways. Few themes call for as much of a blending of mind and heart as that of the Holy Spirit. The global spread of Pentecostal Christianity, often in context of urban poverty, has attracted much attention. The movement highlights a hunger for the experience of God in our world and provides millions of poor believers with hope for social transformation. Yet spiritual experience needs a fully biblical understanding of the Holy Spirit with which its claims can be properly assessed. Ivan Satyavrata provides an introduction to the Bible's teaching on vital issues and questions, many of which have been, and continue to be, a source of confusion and controversy amongst Christians. Combining scholarly enquiry with accessibility, his deep theological reflections and passion for unity will contribute to constructive dialogue and appeal to a wide readership.