What is the religious defense of this Jesus Christ quote?

[Sheldon]

The Genesis creation myth, and the Noah flood myth, are two examples that not only contain risibly erroneous claims, but whose core message is contradicted by objective scientific facts.

Here of course you're assuming that you know what the "core message" of these stories is, and that this is something that can be contradicted by objective scientific facts. 

No, I am merely reading the texts without any subjective interpretation, the geological record demonstrates unequivocally no global flood has ever occurred. The Genesis creation myth gets the most basic chronological facts about the formation of our solar system wrong, and is at odds with species evolution. So again there is no assumption on my part, I merely state the facts.

Myths, allegories, etc., carry a core message that is not dependent on the scientific accuracy of the story. 

Well of course, that's why they're called myths, but then so do Spiderman comics and Harry Potter novels, I am not sure I see your point here? 

Do you have some historical evidence that the stories are intended as literally true?

Did I claim that, I am not sure I did? If on the other hand you are claiming they are allegory though, then you would need to demonstrate something beyond bare assertion, and the fact they otherwise fail in the face of just a few hundred years of human scientific endeavour, something a deity with limitless knowledge to create a message,  and limitless power to convey it, cannot realistically be claimed to have not known would happen. I must ask, why do you imagine, hypothetically of course, such a deity would need to deal in primitive and erroneous allegory, that a) reflect the human ignorance and superstition of the epoch from which they emerged, and b) would so easily be falsified in a very short time by one species of evolved apes, that apparently are supposed to be the main show? Personally I don't find this moving of the goal posts at all compelling. 

Many Christians (e.g. Augustine) assume that their purpose is something other than reportage.

Well see my previous objections to this rationale, and then explain why should I care about the subjective and unevidenced assumptions of others, especially when their bias in starting form a position of credulity is manifest?