This paper explores sacred art museums as dialogical arenas in which religious identities and boundaries are negotiated through performative interaction. Drawing on an ethnographic case study of the AMIR (Alliances, Museums, Encounters, and Relations) project in Florence and Fiesole, it examines intercultural and interreligious performances at the Bandini Museum of Sacred Art, where migrants of diverse religious backgrounds publicly interpret Christian artworks from the fourteenth to sixteenth centuries. The analysis conceptualizes these guided performances as situated practices of interreligious encounter that operate beyond formalized dialogue. They involve a performative reconfiguration of religious "face" in a Goffmanian sense, enacted through narrative strategies grounded in familial universals—most notably the mother-child relationship—and autobiographical memories of popular religiosity. Such narratives produce unexpected intersections between religious traditions while simultaneously articulating moments of tension, exclusion, and cognitive dissonance. In doing so, they destabilize taken-for-granted theological and iconographic assumptions and disrupt audience expectations largely oriented toward perceiving religious difference. Methodologically, the study is based on ethnographic observation of live performances, audio recordings, and in-depth interviews with performers and museum staff. The findings show how the unexpected emergence of perceived similarities generates interpretive disorientation and opens spaces for reflexivity among participants.