Now, it’s true that we are likely to believe a witness when he says things that are not to the advantage of his case. So when the evangelists include stories and sayings which are awkward for their case that Jesus is the sinless Son of God (such as Jesus’ baptism, or the fact that he doesn’t know things, or the fact that he can’t heal people sometimes, or the fact that he cries out “My God, my God, why have you forsaken me?”) that does make the case very strong that the evangelists are honest men.
Only, guys like Gopnik and his audience don’t conclude the evangelists are honest men. Instead, they mysteriously conclude that only these particular passages are honest passages, while the rest of the gospels (written by the same guys who wrote the honest passages)are still completely unreliable works of pious fraud. That’s abnormal. When normal people meet honest people willing to say things damning to their own case, we don’t believe them only about those specific things, we believe them about everything they say. They may be mistaken in their views, but they are not deceptive. When liberal NT critics meet honest men, they believe them only about things their own anti-supernatural prejudices want to believe. When they bear witness to the supernatural (like the Virgin Birth and the Resurrection), they find elaborate ways of declaring them liars and fools, by the polysyllabic route of labelling them “mythmakers” or victims of mass hallucination.
How this plays out includes the standard trick of taking various gospel accounts of the same event/saying and pretending that all variations mean the thing never happened, or that it happened but is buried under a thick layer of mythology that makes the original event impossible to discover. What never occurs to liberal biblical scholars is that you could do exactly the same thing with the assassination of JFK and “prove” that JFK never existed and that the “assassination” of the Kennedy Event is a mythic construct cobbled together by later generations. Three shots? Four shots? From a dozen different directions? Kennedy said nothing? Kennedy said, “My God, I’m hit.”? And what about the Eucharistic significance of a supposed Harvard man announcing a year or two earlier “I am a jelly donut” to the crowds in Berlin? Why is there a doublet in the ancient records that announces the assassination of another “Kennedy” named “Robert”? at almost the same period of time. Clearly, we are looking at the convergence of two mythic tales from the Dallas and Los Angeles faith communities which later redactors smoothed into a single narrative.
Nobody believes such rubbish about historical characters from secular history. But when it comes to Bible characters, our leading lights in liberal biblical scholarship talk as though they are 2000 years smarter than the biblical authors and readers all the time...