Sor Juana’s Respuesta a sor Filotea (1691) is one of her most widely read works and an established text in the history of women’s writing. Less frequently studied is the epistolary exchange to which it responds, particularly Juana’s Crisis sobre un sermón (or Carta atenagórica, 1690), her response to a sermon by the Portuguese Jesuit Antonio Vieira on Christ’s greatest fineza, or demonstration of love. In the Crisis, Sor Juana puts into practice what she would later argue in the Respuesta: that women could, and should, engage in theological study, and that a woman’s well-reasoned argument would defeat any man’s ill-founded and unorthodox thought. This is the first annotated, critical edition and English translation of the complete published exchange between Sor Juana and Manuel Fernández de Santa Cruz, with a comprehensive introduction, commented textual variants, and extensive textual notes. The introduction explores how the Crisis can be read in relation to Juana’s other works, including her love poetry, her eucharistic drama El mártir del Sacramento, and Primero sueño. By analysing its central themes, this study argues that the Crisis is key to Juana’s defence of women’s learning, while also shedding light on her views on gender, theological enquiry, and the dynamics of love, both religious and secular.