The following podcast was preached at Fresh Wind, June 23, 2013:
Re: Background research for authorship, dating, and occasion I did my best to let go of both evangelical assumptions about what must be and liberal assumptions about what mustn't be. In the end, the research I found most thorough and arguments I found most compelling did point to Johannine authorship (John the evangelist or possibly a protege steward of his tradition, if John the elder were in fact a separate figure).
Internal evidence, tradition and external evidence, including archaeology and early allusions, led me to lean toward the majority conservative view of a mid 90's composition, probably occasioned by and directed toward disputes connected to the synagogues (Pharisee party Jews vs. Christian Jews--cf. David Rensberger, Johannine Faith and Liberating Community) in Asia Minor (though with possible roots in Judean vs. Galileen communities). Relevance to Christian struggles with Gnostic heresies were more likely much later applications of Johannine theology.
In terms of those whose research I found most meticulous and current--and less speculative--I leaned tooward Craig Keener (Gospel of John, 2 Vols.) and Richard Bauckham, Jesus and the Eye-Witnesses and The Testimony of the Beloved Disciple. Because of the brevity of the message, I briefly dismissed the radical skepticism of Spong as passe, but did not have the time to deliberate on the strength of other views, most notably John Meier in his marvelous series, A Marginal Jew (4 Vols.).
For a sample of Keener's approach, click: Assumptions-in-Historical-Jesus-Research.
P.S. Sadly, at the last moment, I grabbed a different Bible than I had prepared with--the quite readable NET translation--but didn't notice until too late that 3 of the verses in the Scripture reading were in highlighted boxes but not in the main text! And they are obviously important enough to have been highlighted, so I provide them here in that translation, if only to entice readers further:
v. 5 "And the light shines in the darkness, but the darkness has not mastered it." (NET)
v. 23 "John said, 'I am the voice of one shouting in the wilderness, Make straight the way for the Lord, as Isaiah the prophet said." (NET)
v. 39 "Jesus said, 'Come and you will see.'"