The 4,000 B.C. date for creation is based on a flawed understanding of Biblical genealogies. When one understands the ancient process of "telescoping" (skipping over multiple generations when recording genealogies, which has been proven to have been done in at least some portions of the Bible), the Biblical genealogies actually point toward creation likely having taken place anywhere from 10,000 to 60,000 years ago.

Here's a well-researched article explaining this:

https://web.archive.org/web/20161120174551/http://godandscience.org/youngearth/genesis_genealogies.html

The 4,000 B.C. date for creation is based on a flawed understanding of Biblical genealogies. When one understands the ancient process of "telescoping" (skipping over multiple generations when recording genealogies, which has been proven to have been done in at least some portions of the Bible), the Biblical genealogies actually point toward creation likely having taken place anywhere from 10,000 to 60,000 years ago.

Here's a well-researched article explaining this:

https://web.archive.org/web/20220104180256/http://godandscience.org/youngearth/genesis_genealogies.html