Investigating the complex interactions between devotional imagery and Church doctrine in the Low Countries during the fifteenth century, this book demonstrates how the pictorial arts intersected with popular religious practice. The author reconstructs the conceptual frameworks underlying the use and production of religious art in this period and provides a more nuanced understanding of the use of images in the process of soul formation. This study delves into the complexity of the early modern system of personal justification and argues that religious images and objects were part of a larger 'Technology of Salvation.' In order to make these connections clearer, the author analyzes selected works by Geertgen tot Sint Jans (Little Gerard at St. John's) and shows how they functioned within their larger social and historical milieu.