This article proposes a theological interpretation of Jean-Luc Marion that accents the importance of prayer as a remedy to conceptual idolatry. It also addresses theological concerns about Marion's understanding of the relationship between phenomenology and theology, and about his critical attitude toward ontology. In response to the first concern, it uses Marion's readings of Dionysius the Areopagite and Augustine to demonstrate that Marion prioritizes a prayerful approach to theology that transcends phenomenology, even while benefiting from it. In response to the second concern, it draws on Marion's treatments of Dionysius, Augustine, and Aquinas to show how the same prayerful theology accommodates an ontological way of praising God. Prayer is the key to both arguments. Prayer resists the conceptual idolatries operative in the realms of phenomenality and of being, while revealing the potential iconicity of both. Finally, this article clarifies why Marion's recent Augustine book is crucial to an understanding of his project.