The article identifies the main problems of the theory and practice of collecting empirical data, on the basis of which one can build objective judgments about the level of religiosity of the population and its religious composition. The advantages and disadvantages of a sociological survey, population census data, and official data provided by religious organisations as sources of this type of information are considered.
The Evangelical Lutheran Church of Denmark (ELCD) is chosen as an example. It is considered by the author as a constructive example of a majoritarian religious organisation, reflecting over the dynamics of several decades quantitative data on the number of adherents and the degree of activity of their religiously determined behaviour. In the regional aspect quantitative data on the absolute and relative number of participants in religious ceremonies, on the registration of births, marriages and deaths, etc. are reflected. Information on the number of baptisms, confirmations, weddings, funeral services is provided at the level of individual dioceses of church-administrative units at the regional level. Based on the obtained results, territorial differences in the level of religiosity of Danish residents are recorded. The minimum indicators characterise the capital region with a high share of migrants – representatives of non-traditional cultures in the population structure. At the same time, the high degree of religious activity of ELCD adherents distinguishes the territories of mainland Denmark remote from the administrative center (Viborg, Aalborg, Ribe).
The results of the analysis of initial data concerning the total number and share of baptisms, confirmations, church marriages and funeral rites performed in the ELCD in recent years confirm the general secular trends characteristic of the population of Western and Northern European, primarily traditionally Protestant countries. Official statistical databases of religious organisations, recording both membership in them and participation in religious sacraments and rituals, are positioned as the most representative source of initial information for solving the problem of identifying the religious structure of the population and determining the level of its religiosity. The considered example of collecting and processing information is effective, but at the national and regional levels it is implemented only in cases where the model of religious-state relations provides the appropriate tools.