There are many competing and complementary applications of ideas of uncertainty and in this chapter we outline these as well as showing how the key themes arising across the chapters interlink and provide a picture of the impacts of uncertainty on fringe ideological movements. The chapter compares and contrasts themes from the chapters focusing on religious groups with those on secular groups, demonstrating both the similarities in issues and responses as well as what can be seen to be unique about religious responses to uncertainty. It also highlights how uncertainty can be variously conceived, both in the theoretical study and experience of these groups, in the shape of external threats, such as legal pressures, and internal change, such as theological innovation, or the death of a founder. While each of the chapters that follow will stand on their own merits, this chapter both guides the reader through how they contribute to a cohesive whole, while also serving as an introductory guide to the problem of uncertainty as an everyday experience for individuals and groups, with a particular focus on minority religions.