Across Europe, changing patterns of religious practice have left many churches underused or redundant, prompting debates about how to preserve their architectural and cultural value. In Poland, where Roman Catholicism continues to play a significant social role, the question of what happens to former or partially deconsecrated churches is particularly sensitive. Adaptive reuse has emerged as a possible response, offering ways to protect historic buildings while allowing them to serve new social and cultural purposes. Yet such transformations raise a central question: how can the liturgical past of these spaces be preserved when their original function has changed? This paper examines adaptive reuse of Roman Catholic churches in Poland, focusing on how heritage values and new functions attempt to maintain traces of the buildings' liturgical identity. The study analyzes selected Polish case studies in which churches have been converted into cultural, educational, or community spaces while retaining elements of their sacred character. The paper explores architectural strategies and heritage practices that preserve liturgical memory, such as maintaining spatial hierarchies, conserving altars or iconographic elements, and respecting the symbolic orientation of the building. Rather than erasing the sacred past, many projects seek to reinterpret it, allowing the former church to remain recognizable as a place shaped by worship and ritual. By examining these examples, the paper argues that adaptive reuse can function not only as a tool of preservation but also as a way of safeguarding the liturgical and symbolic heritage embedded in sacred architecture. Such projects reveal how memory, material heritage, and new social uses can coexist within transformed religious spaces.