Can Christians argue the Earth is only 6000 years old?

In today's post by vjack on the Atheist Revolution blog, he makes the claim that sometimes Christians hide behind the "agree to disagree" statement in order "not to give serious reconsideration of his or her position." This argument definitely goes both ways. I have had similar discussions with Atheists who would pull out the "agree to disagree" or more often I find Atheists are quick to bring up Leprechauns and trolls as a way of relating Christianity to something ridiculous when their arguments come up small. But I digress.

The part of his post that made me think was "The claim that the Earth is 6,000 years old is factually false. Overwhelming evidence contradicts this claim. If the Christian makes this claim and I challenge him, we cannot very well agree to disagree."

Can a Christian argue that the Earth is only 6000 years old?

I am not going to pretend to know a lot about the aging process, or the testing of the age of the earth or anything else for that matter. I will agree with vjack that there is overwhelming evidence that contradicts the claim that the earth is only 6000 years old. On the other hand, Christians that argue that the world is only 6000 years old, almost always have the stance that God created the world with age. Basically that if God had created everything new, things wouldn't have functioned correctly. For example, when God created trees, he probably didn't just put seeds in the ground, he most likely just created a fully formed tree.

Now, I am not trying to argue that the world is only 6000 years old, but I will say that the argument can't be dismissed as ridiculous. If someone holds that view they can "agree to disagree" with someone who holds a view of a much older earth. It does not as vjack put it, "suggest that the Christian is delusional".