Well I for one "know" that the earth is older than 4,000 years. How? Because when I go outside at night and I look up, I see stars. Stars that are more than 4,000 light-years away. And an old-earth is not incompatable with The Word of God.

Don't get me wrong. I also "know" that the earth is older than 4000 years. But I've actually talked to a number of Christians who tell me that's not only insane, it's heretical. But, again, I don't mean to imply that all Christians feel that way.