Heinz Streib (M.A. 1977, Tübingen University; Ph.D. 1989, Emory University, Habilitation 1995, Frankfurt University) is Senior Professor at Bielefeld University. He has established the Research Center for Biographical Studies in Contemporary Religion at the University of Bielefeld and has conducted there a series of empirical studies. Streib's major third-party funded research projects are the following: Fundamentalist Biographies (1996-1998, for an Enquete Commission of the German Parliament); Varieties of Deconversion in the USA and Germany (2002-2005); Semantics and psychology of "spirituality" in Germany and the USA (2009-2012); Xenosophia and Religion in Germany (2011-2015); Longitudinal research on religious development with the Faith Development Interview as key instrument (current). Key research interests include: Theory and longitudinal research in religious development in terms of religious styles and schemata; violence and inter-religious prejudice in Europe; Children's and adolescents' readiness for mediation.

Constantin Klein (Dipl.-Psych. 2003, Leipzig University; Dipl.-Theol. 2004, Leipzig University; Ph.D. 2013, Bielefeld University) is Professor for Spiritual Care at Ludwig-Maximilians-University München. Between 2009 and 2017, Klein was scientific assistant at Bielefeld University and associated with the Research Center for Biographical Studies in Contemporary Religion. Klein was primary researcher for the research project "Xenosophia and Religion in Germany" (2011-2015), the results of which are presented in this volume. Key research interests include: Theory and research in the psychology of religion; violence and inter-religious prejudice in Europe; spiritual care.