One of the great challenges for the study of so-called 'popular religion' is related to understanding and assessing the theological status assumed by the various art forms through which this phenomenon is expressed. Within the framework of the research project 'Art and Apophatism: Epistemological Foundations of a Theology of Art' (Fondecyt No. 1230439), a method of analysis is proposed for the various religious expressions that give substance to popular religion, and more specifically, to religious festivals. This is a performative phenomenon in itself, and its apophatic principle would consist precisely in the impossibility of accessing it and the knowledge that emanates from it without the active participation of the observer, which involves psycho-affective dimensions. In addition to being a particularly fertile topic in the field of contemporary aesthetics, apophatism is a fundamental part of the early understandings of Christian epistemology. Along with presenting the theoretical and methodological foundations of the proposal, case studies will be presented that illustrate the points made in this paper.