This study shows how classical Greek and Hellenistic philosophical and ethical traditions inform Paul's Letter to the Romans. It concentrates especially on Protreptic, a kind of literature deriving its name from the title of a lost writing of Aristotle that has been largely reconstructed by scholars in our time. The Protreptic writers seek to awaken their readers to a realization of human frailty and then to commit themselves to a new way of life. Guerra shows also how the political conditions of Nero's Rome are reflected herein.