This text is linked to the aspects of power relations in the Vita Sancti Aemiliani in Vita Sancti Fructuosi and autobiography of Valério of Bierzo: Christianization and ecclesiastical reorganization of the Visigothic kingdom in the seventh century, funded by CNPq. Among other assumptions, this research recognizes that the ecclesiastical authorities at the beginning of the Middle Ages worked for the promotion of a comprehensive education program, which was associated with standardization and education of lay and clergy. In this process, the hagiographic literature has assumed a prominent place. Considering the autobiography written by Valerius of Bierzo as an expression of the hagiographic genre, it is intended in this article, based on the historiographical reflections of ecclesiastical activity in the Hispanic peninsula in the sixth and seventh centuries, discussing the role played by the devil in such a report, sometimes more sharply expression a literary topos, now speaker of the specific situation of the author.