Keener’s commentary explores the Jewish and Greco-Roman settings of John more deeply than previous works, paying special attention to social-historical and rhetorical features of the Gospel. It cites about 4,000 different secondary sources and uses over 20,000 references from ancient literature.

"Sixteen hundred pages is a lot of pages for a commentary on the Gospel of John, surpassing Raymond Brown and almost matching Rudolf Schnackenburg’s three volumes. But Craig Keener has given us far more than a commentary. He has invited us into the world of that Gospel and made it a magnificent window into the thought and practice of early Judaism and, to a lesser extent, the whole Greco-Roman world of the first century. At the same time, he has made those first-century worlds a lens through which to view the Gospel of John itself. The reader will find this work a treasure trove of information about the origins of Christianity, shedding light on such questions as what is a Gospel? how reliable are the four Gospels in their portrayal of Jesus of Nazareth? and in particular how reliable is the Gospel of John? Keener presents a compelling case for viewing Jesus himself within the framework of early Judaism, and for both the Jewishness and the essential reliability of the traditions about Jesus preserved in John’s Gospel. Keener’s introduction runs to well over three hundred pages, and his bibliography to almost two hundred.