The author focuses on the problem of ambiguity of religious concepts (religiosity, secularism, conversion) and their use in various social sciences. Historians, sociologists, demographers, theologians use for their other methods.
Using of quantitative methods represents some contents, but the historical actors could use other means of their spiritual experiences. A historian can not have a pastoral interview with them, but he can search various levels of the religious culture of actors.
The aim of the study is to present the variability of historical processes, which surrounded the changes of religiozity, the secularization and conversions in Central Europe in the Modern Age. The question is, how different were using of the term conversion in various confessional cultures, how much important were confession, theology, religious education etc.
In conclusion it is said the general trend is not a global secularization, but variable religious culture, which goes again through revitalization or resurgence of religion. Also the theological semantics of conversion has changed in the Modern Time.
The aim of the study is to search the actor in his culture.