According to Genesis, Adam and Eve were created about 4000 BC (Gen. 5 & 11)...
In general, this is an excellent post. I’m just going to pick on this one statement–because it reflects a common, subconscious conflation.
Genesis doesn’t place the creation of Adam and Eve anywhere on our calendar. Assuming the days of Gen 1 are consecutive calendar days, assuming the genealogies have no gaps, it remains the case that Genesis doesn’t date the creation of Adam and Eve to c. 4000 BC.
That’s because the Bible doesn’t give us a continuous calendar marking off the days from the moment of creation to the current date. What the Bible gives us is a rough, internal, relative chronology.
I say it’s “rough” because it doesn’t give us a day-by-day sequence. I say it’s a relative chronology because it places some recorded events earlier or later than others. And it supplies a terminus ad quo or time-zero at the moment of creation. But it doesn’t give us an absolute chronology. Rather, it gives us a set of internal relations.
What’s really involved in calculations like this is an effort to correlate Genesis with our calendar. We begin with a chronology of the ANE, then try to intercalate Genesis somewhere in that framework.
So we’re dealing with a hybrid chronological construct, which has both biblical extrabiblical information feeding into it. And, of course, a chronology of the ANE is a complex historical reconstruction, with various methods, assumptions, and interpolations.
When we talk about the date of creation or the date of the flood, it’s important to distinguish between biblical and extrabiblical considerations.
This goes to a point of tension in young-earth creationism. On the one hand, creationism is sceptical of standard cosmological and geological dating techniques. On the other hand, creationism tries to time Noah’s flood or the origin of the world within narrow parameters. It would make more sense for creationism to be consistently rather than selectively sceptical about standard dating techniques.