This dissertation examines the writings of Augustine of Hippo which pertain to the angels. Although patristic angelology has received little scholarly attention, the presence of mediating spirits was assumed in antiquity, and they frequently appear in both Augustine's theological writings and in his homilies. According to Augustine, the angels are holy and wholly aligned to the will of God, and so in the life of the angels, we can glimpse Augustine's view of the perfection of creation. In this dissertation, I pursue four main topics of discussion in order to illuminate the theological and pastoral implications of Augustine's understanding of angels: angels and creation (chapter one), angelic community (chapter two), angels and salvation history (chapter three) and spiritual warfare (chapter four). In pursuing these four subjects, I demonstrate that Augustine does not treat the angels in abstraction, but as creatures of God. Their existence confirms the goodness of creation and in their life we see the perfection of created goodness, that is, the perfection of bodies, of sacraments, of worship and of cooperation in the plan of salvation. I argue that the chief theological import of Augustine's view of the angels is that they demonstrate his commitment to the idea of the goodness of created communion. The city of God, whose first members are the angels, are not just created good or created in communion with one another, but created good as communion from the very beginning. It is this community which human beings long to join in the future, and yet are now already a part.