For the first time, individual appropriations of relating to the ultimate will be investigated in a comprehensive longitudinal study, and test whether there is in fact faith development over the life-span and what correlates with such development. Thereby ‘faith’ embraces individual ways of relating to the ultimate including vertical and horizontal transcendence (Streib & Hood, 2013). This project capitalizes on experience and data collected in more than ten years of cross-cultural research with a special focus on the exploration of faith development with qualitative and quantitative methods: Our data include hundreds of faith development interviews (FDI) conducted according to Fowler’s (1981) interview format, and, for most of the same respondents, extensive quantitative data on psychological correlates. This allows for a first round of re-interviewing and longitudinal assessment. The second major output of this research is the preparation of a large-scale longitudinal investigation by the construction of, and first-time FDI interviewing of, a sample of ca. 300 respondents in the US. This project is more than simply a replication of FDI research: Recent revisions of Fowler’s model by Streib´s program of religious styles (Streib, 2001; 2005; 2013) intend to avoid dead-ends in cognitive-structural “hard” stage theory and model “development” as more flexible and a s multi -dimensional. Streib’s quantitative instrument, the Religious Schema Scale (RSS, Streib, Hood, & Klein, 2010) is part of that innovation. The joint application of the FDI and the RSS allows the assessment of developmental change of schemata and narrative constructions. Such innovations and the inclusion of additional evaluation perspectives such as attachment, mentalization or wisdom (Keller & Streib 2013), will guide a new revision of the Manual for Faith development Research, as an additional output, which will be used in the training in this project already.