Paraenesis developed in early Christianity through the example of Paul's epistolary moral exhortation. Two social conditions that were vital to the rhetorical power of Pauline paraenesis were his personal acquaintance and friendship with the recipients, allowing him to write in a spirit of philophronēsis, and the particular theological worldview he shared with his churches. Post-apostolic church leaders continued to write moral exhortation to their congregations, but the tone and motivation of second-century paraenesis differs from that in the New Testament. This paper seeks to understand what has changed in second-century Christian paraenesis and why. It suggests that differences from first-century apostolic paraenesis might be explained in part by three observations: (1) second-century authors wrote more often from a position of formal authority than the philophronēsis typical of Paul; (2) a shift has occurred in theological emphasis, which affects how moral exhortation is motivated; and, closely related to the second point, (3) inroads made by a growing appreciation of Platonic thought influence both the shape and the goals of Christian moral exhortation. The paper takes into account paraenesis in second-century writings to Christian congregations: 1-2 Clement, Ignatius, Polycarp, Barnabas, Martyrdom of Polycarp, and Clement of Alexandria.