This volume is the first major English-language commentary on the Epistle to Diognetus since that of Henry G. Meecham in 1949. Its purpose is twofold: to provide careful consideration to the essential introductory issues of authorship and setting, structure and integrity, theology, relationship to scripture, and historical trajectory as they apply to the transmission of the text; and to offer commentary focused on the movement of the author's argument and objectives in construction of the narrative, taking advantage of critical considerations of the apology within recent scholarship. In the final analysis the volume arrives at the premise that the core materials of Diognetus were likely delivered first in an oral context whose setting remains unknown and were thereafter recorded by a later hand as the framework of chapters 1-10. A subsequent editor (perhaps Clement of Alexandria) added the concluding materials of chapters 11-12 together with the insertion of numerous hymnic segments and theological phrases throughout chapters 1-10. These additions were inspired by Johannine tradition and reflect the setting of a living faith community. The text of Diognetus thus reflects an evolutionary process that moves from oral performance to literary record, from moral teaching to theological homily. The format of the volume is designed to welcome the non-specialist to the text of Diognetus while exposing the reader to the best of both earlier and more recent critical comments on the writing and its tradition.