This paper looks into the 200-year history of a particular Christian dress form in Finland, namely the körtti dress. Emerging from a declining peasant dress style, this supposedly unchanging and fossilised signifier of a revivalist Protestant movement has in fact gone through numerous transformations influenced by both socio-political and religious trends as well as fashion-driven and materially-ordained factors. From the analysis emerge four key factors that influence how dress strategies are formulated and enacted within a religious movement: (1) how vulnerable or institutionalised the movement is; (2) how it is viewed by those external to it; (3) how the members of the movement want themselves to preserve or change the movement and its public image; (4) and how external fashion processes infiltrate the tastes and sensibilities of the members. It is concluded that elements considered ‘traditional’, ‘modern’, ‘secular’ and ‘religious’ may all be present at the same time in a dress phenomenon, indicating that fashion’s association with modern secularity is not as clear-cut as is sometimes thought.