The paper focuses on the topic of conceptualizing religion in Czech society today from the perspective of the Study of Religions. The paper further develops and assesses in theoretical terms the findings of descriptive content analysis published by Veronika Hásová and Jan Váně (2014), who identified and quantified the frequency of variables of religiosity applied by researchers in the Czech Republic. The characteristics applied most frequently are categorized as functional characteristics (religious affiliation, church attendance) and substantive characteristics (belief in diverse religious phenomena) of religiosity. Results and conclusions of the analysis of religiosity in the Czech Republic depend heavily on how the functional and substantive characteristics of religiosity are conceived and formulated. The functional characteristic of religious affiliation conceived in terms of church membership results in a low measure of religiosity and supports the conclusion concerning the purported irrelevance of religions and religious identities in the Czech society today. Other surveys based on different conceptualizations of religious identities reveal the relevance of religion as far as the attitudes and values of respondents are concerned. Topics connected to religions and religious identities continue to be discussed within the public sphere of Czech society, e.g. through the media. As far as the substantive characteristics of belief in religious phenomena are concerned, the specification of the subject of such belief is of vital importance. As surveys of religiosity reveal, respondents relatively often declare their belief in or reliance on phenomena connected with alternative religiosity or spirituality. The ways of conceptualizing religion in Czech society today often ignore the dynamics of religious change in modern societies and do not take into account changes in the perceived content and functions of religious phenomena. Critical examination of the variables of religiosity leads towards a re-examination of conclusions concerning the purported irreligious or secular nature of Czech society today