Measures of Spirituality/Religiosity—Description of Concepts and Validation of Instruments

Why do we need some more questionnaires to measure aspects of spirituality/religiosity when we already have so many well-tried instruments in use? One answer is that research in this field is growing and that new research questions continuously do arise. Several of these new questions cannot be easily answered with the instruments designed for previous questions. The field is expanding and, consequently, the research topics. A further answer is that several of the already established and conceptually very clear instruments are rather ‘exclusive’ as they are specific for distinct groups with circumscribed views and religious orientations. The disadvantage is that they are not inclusive enough to be used for persons with distinct spiritual views or even secular perspectives. To overcome this problem, multidimensional instruments were developed which cover existential, prosocial, religious and non-religious forms of spirituality, hope, peace and trust—and several more. The disadvantage of these ‘inclusive’ instruments is the fact that some are conceptually broad and rather unspecific, but they might be suited quite well for culturally and spiritually diverse populations when the intention is to compare such diverse groups. On the other hand, some of the instruments may be ‘contaminated’ with personality traits and dimensions of mental health and wellbeing, and thus the results might be ‘false positive’ because they do not measure specific aspects of spirituality (with the multiple attempts made so far to define it). In fact, there is a multitude of definitions, ranging from ‘exclusive’ to ‘inclusive’ definitions. Two statements may exemplify this: