In this presentation, I explore the implications of the material turn in the study of religions for scholarship on lived religion during communism. Based on the findings of the Hidden Galleries ERC project (hiddengalleries.eu), which focused on the archives of the secret police in Hungary, Romania, Moldova and Ukraine, I suggest ways in which the insights and methods employed by scholars of religions can help us access the agency, and creativity of religious communities under surveillance, and in so doing reveal the processes of religious change that have helped shape contemporary Central and Eastern Europe. The secret police archives contain an array of confiscated items such as photographs, artworks and pamphlets, as well as diaries, poetry, letters and postcards. These materials are, however, embedded within files compiled, curated and edited by the secret police agents, who engaged in their own creative practices of visually representing, for the purposes of investigations, criminal cases and propaganda, those that they were charged with destroying or discrediting. Using examples from Romania and Moldova, I will present the multi-layered, hybrid assemblage of texts, items and images that comprise the secret police holdings on religions and illustrate how an ethnographic attentiveness to materialities can contribute to our understanding of the past.