Opinion of this meme

[Statilius the Epicurean]

I am somewhat suspicious of the liberal “Christianity” from which sentiments like this often spring, in part due to its overreaction to the exclusivist Christianity which began its own errors with Augustine. To many progressive Christians, ecumenism represents an attempt to syncretize perfectly fascinating systems like Platonism or ancient Egyptian religion with Christianity to the destruction of the church.

The exclusivist Augustine would hate progressives trying to syncretise Christianity with Platonism.

[Statilius the Epicurean]

the Gospel writers only clearly show relating the story to the OT and not, say, to mystery Greco-Roman religions or Homeric epics.

In general this is true but there are some instances in the NT where we can see the influence of Homer. The most obvious example I know is the story of Eutychus in Acts 20 being a transvaluation of Elpenor in the Odyssey.

[Statilius the Epicurean]

the Gospel writers only clearly show relating the story to the OT and not, say, to mystery Greco-Roman religions or Homeric epics.

In general this is true but there are some instances in the NT where we can see the influence of Homer. The most obvious example I know is the story of Eutychus in Acts 20 being a transvaluation of Elpenor in the Odyssey.

That's really a stretch. The only link between the two is that both prefigured Humpty Dumpty by taking a great fall. Tho obviously the tale of Humpty Dumpty was more influenced by Elpenor than Eutychus since like Elpenor, Humpty Dumpty was not put back together again.

The reasons why they fell, their end fate, and their use within the narrative were completely different. It's a fevered take from a grad student desperate for a thesis topic to satisfy a professor who thinks much of the New Testament was a response to the Homeric tradition.

The allusion is more than both falling down: e.g. both Elpenor and Eutychus are only picked up the next day by their comrades, which is kind of inexplicable in the Acts narrative. There are linguistic parallels, notably the use of the same word for roof that is found nowhere else in Luke-Acts (and only one other place in the entire NT).  Elpenor is called "unlucky" in the Odyssey, the name Eutychus means "lucky". And where does the author of Acts place the story? While Paul is visiting the city of Troy.

Elpenor was a famous character in ancient literature and his story was also reworked by among others Plato in the Republic, and Clement of Alexandria references him by name (don't be drunk like Elpenor was). Any educated Greek reader, having been drilled on Homer since they were a child, would have immediately grasped the allusion and its moral: the pagan afterlife is death, the gospel of Paul is life.

There are likely other Homeric allusions in the New Testament but the above is the one I'm most familiar with.

[Statilius the Epicurean]

MacDonald is sort of the epitome of the bad scholarship which often comes out of Claremont and, to a lesser degree, Harvard and Yale. The idea that the Gospels are closer to Homeric epics than, say, to Plutarch’s Parallel Lives is just demonstrably false to anyone who has ever read the two. Luke is clearly familiar with the normal historiographical practice of his day, of the sort we find in Plutarch and Tacitus and, in a more biased history, Cicero. His careful and rigorous documentation of fact after fact comes often at the expense of prettier if false narratives, although he does have a few ideas of concealment in common with Matthew and Mark.

I don't find MacDonald's grand theories like all of Mark is a rewriting of Homer very persuasive. But he's clearly right that there are Homeric influences in some places in the NT. Elpenor/Eutychus is the most obvious example. 

I could say more about ancient historiographical standards but that wouldn't be really relevant.