Why do traditions disappear? How is the disappearance of tradition also a vehicle for social change and re-inventions of practices and new traditions? Using case studies from one Sukuma area along the southern shores of Lake Victoria in Tanzania, global processes of how religions work in practice are analysed by focusing on rainmaking, witchcraft and Christianity. Traditionally, Sukuma society was culturally and cosmologically structured around the chief, the ancestors and rainmaking. Everything was dependent upon the rain. Rainmaking as a ritual practice has disappeared and ancestral propitiations are declining, while, at the same time, Christianity is spreading and witchcraft and witch killings are increasing. Although Christianity as a religion may provide answers and hopes for life after death, the religion provides few solutions in the here and now when it comes to poverty and suffering; problems and challenges that have to be solved. Witchcraft, on the other hand, does, or is believed to do so - and the increase in witchcraft is analysed in relation to the impacts of more than a century of globalisation from the missionaries and colonizers onwards. With the declining ancestral tradition, witchcraft and Christianity as religious practices supplement each other in the ways they are believed to work in providing answers, solutions or divine interferences in different realms; this world and the Otherworld. Offering an approach going beyond structural functionalism on different premises, the book's focus on religion at work will facilitate new understandings of how to study religion as it is perceived and believed in practice.