In his brief comments on the Abraham-episodes of Genesis 15:1–11, Emperor Julian the Apostate indirectly attacks the apostle Paul's interpretation that Abraham exhibited πίστις as a justifying ‘faith’. Through a close reading of the biblical text, he interprets Abraham as, rather, receiving a divine πίστις—a ‘pledge’ or ‘confirming sign’—during two theurgical rituals. Although modern scholars have overlooked Julian's subtle argument, Cyril of Alexandria recognized Julian's strategy and responded directly. Attention to Julian's and Cyril's competing accounts shows that different conceptual grammars, tied to rival traditional narratives, lay behind their incompatible claims to Abraham and his πίστις.