If you can attack the Bible at it's very core and prove or demonstrate that it is incorrect in it's assesment of how we got here, the entire credibility of the Bible is destroyed. Since according to the Bible, the first 5 days of creation were only witnessed by God, then if the account is wrong, then what else could you believe in the book.
etc.
The "if you can't believe all of it, then how can you believe any of it" attitude seems to be a common theme expressed by fundamentalist Christians. This is applied to the Bible in general, and to the creationism of Genesis in specific (and, as a side note, also to the theory of evolution, both biological and in the broader sense of the term).
I think the general content of your message is deserving of being it's own topic. Titled something along the lines of "Bible: Can you believe some of it, if you don't believe all of it". But that may be more characters that the title field will permit.
Cheers,
Moose (with Adminnemooseus looking over the shoulder)
Professor, geology, Whatsamatta U
Evolution - Changes in the environment, caused by the interactions of the components of the environment.
"Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham