This dissertation analyzes the use of Augustine's life and thought, especially as recorded in his Confessions, in the Herald of Divine Love. It argues that Gertrud collaborated with her sisters at Helfta to produce a book adopting, advancing, and inviting readers into Augustine's conversational model of theology. The first chapter introduces Gertrud and Helfta, reviewing the literature and suggesting some modifications to the standard accounts. The second chapter analyzes the work's composition history, described in its Prologue with the feminine and collaborative metaphor of childbirth. The combination of her autobiography with the convent's hagiography expresses God's choice of Gertrud through and for the holiness of others. The third chapter discusses Gertrud's spiritual autobiography in Book II, written in the prayerful style of Confessions. She uses Augustine's image of the pierced heart as a 'book' in which to read God's merciful love, created through conversational narratives connecting personal and communal salvation history. The fourth chapter analyzes Gertrud's 'Life and Revelations' in the compiled portions of Legatus, especially Books I and V. In Book I her sisters advocate a model of female holiness as converted scholarship, comparing Gertrud to Augustine as an inspired theological teacher formed by a holy community. In Book V they conclude the work with divine promises of the book's wonderworking power as Gertrud's relic. Along with Gertrud, the Helfta women offer the Legatus in praise of God and to enable readers' holiness by assisting them to discover and respond to grace in their personal salvation history.