2 Clement

Traditionally attached to Clement of Rome but almost certainly not written by him; the real author is unknown, likely writing c. AD 100-150. Actually a sermon rather than a letter -- the oldest complete Christian homily outside the New Testament to survive, urging repentance and holy living. Chapters 1-11 are in the 1870 Ante-Nicene translation; chapters 12-20, which that edition lacked, are in the 1885 revision of the same translation, so they read slightly more modern.