In most panels, religion is only measured using two to three indicators. This means that only a limited analysis of religion is possible. As a result, there is a great lack of longitudinal knowledge about religion worldwide. In the SHP, religion was measured by four indicators from 1999 to 2009: Frequency of attending religious services at the age of 12 (only when an AP first attended), Current frequency of attending religious services, Frequency of prayer outside of religious services, Affiliation with a church or religious community. This at least made it possible to differentiate between social and personal religiosity. However, spirituality and the dimensions of religious experience and reflection, which are important in terms of individualization theory, were left out.

Since 2012, religion has only been measured in the SHP every 3 years (2012, 2015, 2018, 2021, 2024). At the same time, the religion module was expanded to a total of 16 indicators. A distinction is made between 5 core dimensions (Glock 1962): Ideology (9 items: belief in God or the divine, religious identity, spiritual identity, and attitudes toward 6 religions and worldviews) Intellectuality (1 item: thinking about religious issues), experiences (2 items: frequency of mystical experiences, frequency of experiencing a spiritual entity), private practice (2 items: frequency of prayer and meditation), and public practice (2 items: attendance at religious services today and at age 12). In addition, a scale on the centrality of religiosity (Huber 2003; Huber & Huber 2012) can be calculated from 5 or 7 basic indicators of the 5 core dimensions. This scale indicates the probability of an intrinsic motivation of religiosity (Allport & Ross 1967) and is meanwhile established worldwide in more than 600 studies (Huber et al. 2020).

The differentiated religion module of the SHP opens up new possibilities for investigating the relationship between religion, religiosity and spirituality and other variables (e.g. critical life events, health, life satisfaction, values and political attitudes). In particular, it is now possible to investigate changes in the internal structure of religiosity in the context of secularization, individualization and pluralization of society in a longitudinal section.

In the first paper "Long-term longitudinal stability and change of the centrality of religiosity scale and the structure of its association with spiritual and religious identities" Stefan Huber & Mathias Allemand first focus on the stability and changes in the internal structure of the 5 or 7 basic indicators of the centrality of religiosity scale in their relationship with the two indicators of religious and spiritual identity. In the second paper "Religiosity and Posttraumatic Stress and Growth During the COVID-19 Pandemic" Mathias Allemand et al. examine longitudinal links between level and change in centrality of religiosity and post-traumatic stress and growth during the COVID-19 pandemic. This will demonstrate the analytical and empirical potential of the centrality of religiosity scale. In the third paper "Coping with the death of loved ones. Change and function of different dimensions of religiosity and spirituality and of the centrality of religiosity" Nina Burau et al. illustrate the potential of a differentiated measurement of religiosity and spirituality in relation to coping with the critical life event of the death of a loved one.