Before serving as Bishop of Constantinople and becoming known to posterity as "the Theologian", Gregory of Nazianzus was an Athens-trained professional teacher of Greek literature. Steeped in the rhetorical culture of the Second Sophistic, his orations for Christian feasts such as Christmas and Pentecost belong to a Classical tradition that privileged the performance of philosophy at festivals. Widely copied and translated, they were instrumental in Gregory becoming one of the most popular and influential authors in Byzantium. This book shows how his orations represent a crucial point in the Late Antique reception of Platonism, rhetorical theory, and ancient festival culture.