Plutarch

I'll comment on Licona's interview, which summarizes his book:

https://www.biblegateway.com/blog/2017/06/why-are-there-differences-in-the-gospels-an-interview-with-michael-r-licona/

Most evangelicals are willing to acknowledge that the Gospel authors used some compositional devices.

Agreed.

I first observed how Plutarch reports the same stories in two or more of the biographies he wrote. I then assessed how the same author—Plutarch—told the same stories differently. Then I identified patterns of the differences. I then inferred compositional devices Plutarch likely employed that resulted in those differences.

That strikes me as a fallacious inference:

i) Suppose Plutarch writes three biographies in which he narrates the same event, but there are differences in each telling or retelling. Is that due to compositional devices? Possibly. But consider other explanations:

ii) The account in the first biography is based on his sources. When he writes a second or third biography in which he narrates the same incident, he relies on his memory of what he wrote the first time around.

iii) Conversely, the same story is different in the second biography because he was using different sources for the second biography. Same thing with a third or fourth biography. On (ii) or (iii), the differences are not due to compositional devices. And I think that's at least as plausible as Licona's explanation. 

iv) Finally, it makes no sense to chalk up the differences to audience adaptation inasmuch as Plutarch presumably had the same implied reader for his biographies. 

The majority of New Testament scholars agree that, at minimum, the Gospels share much in common with the genre of Greco-Roman biography. Therefore, it should be of no surprise to observe the Gospel authors using the compositional devices that were part-and-parcel of that genre. In fact, we should be surprised if we did not observe it. 

i) Plutarch was a pagan Gentile who studied at the Platonic Academic in Athens. His background is completely different from at least three of the four Gospel writers. Since they didn't have his training, why imagine that they'd use the same rhetorical techniques? 

ii) Even assuming that differences in the Gospels are due to literary devices, why attribute that to the genre of Greco-Roman biographies? The Gospels are steeped in the OT. The OT is full of literary conventions. OT narratives employ compositional techniques. Is it not at least as likely, if not far more likely, that they are indebted to OT exemplars? 

iii) When I used to ask my late grandmother questions about her life, her answers weren't modeled on literary exemplars. Rather, her answers were based on memory, articulated in her Southern working-class speech. Why assume that all four Gospels must conform to a self-conscious literary genre? Especially in the case of Mark and John, why not use oral history as the frame of reference? 

A truly high view of Scripture embraces the Gospels as God has given them to us rather than forcing them into a mold of how we think he should have.

When Licona doubts or denies that Jesus ever uttered the "I am" sayings in John's Gospel, he's not accepting the Gospel accounts as is. His actual practice is diametrically opposed to receiving the accounts as they come to us. By the same token, when he says the Doubting Thomas anecdote may be pious fiction, that's not crediting the account as God gave it to us, but filtering the account through Licona's screening device.