This talk examines the relationship between religious/ethnic belonging and language, specifically so-called heritage language(s), meaning societally non-dominant languages with which individuals associate an ancestral connection. Instead of discussing fixed categories of religiosity or of language, the approach combines the empirical paradigms of the lived experience of language (Busch, 2012; 2017) and of lived religion (e.g. Hall, 1998; McGuire, 2008; Ammerman, 2021). Through narrative analysis of 21 biographical interviews with members of a German-speaking Protestant and two Reform Jewish congregations in Manchester, UK, the talk presents how emotional-affective experiences related to linguistic and religious knowledge are used to construct and negotiate the relationship between the individual on the one hand, and the congregation, ethnic/religious identity categories, and the divine on the other (cf. Orsi, 2013). The analysis shows that personal religiosity and ethnic/religious belonging is experienced as practical mastery over a wide repertoire of linguistic, religious and other symbolic knowledge (Bourdieu, 1977), making heritage language knowledge a key resource in exercising and contesting religious institutional power (Bell, 1992; Rappaport, 1999). Consequently, the talk argues that a praxeological perspective on (heritage) language and religion (cf. e.g. Avni, 2012; Rosowksky, 2021; Badder and Avni, 2024) is needed to more fully understand the personal and institutional significance of language and religious practices in a contemporary European context characterised by migration and diversity, including in the religious sphere. (Reference list exceeded character limit, available upon request)