You're talking about fundementalists here, not normal christians. You can disprove fundamentals(regardless of which religion) so easily it's quite boring (Plus it doesn't achieve anything as they just ignore you). Besides, the bible never claimed the earth is 6000 years old. You arrive at that number by adding together all the years of the genealogy since Adam and Eve - While completely ignoring that the description of Genesis was never intended to be taken literally, not even at the time of writing. We even know when those passages were written, and why. Yet, it says that there was literally nothing no light, no land, no water. If we are to take it as it is written we would believe that Earth was 6000 years old and these fossils are weird fakes. Yes, if we take it literally. You are not supposed to though. It doesn't make any sense and you were never supposed to. Yet, if we do not take it literally we lose a lot of the power held with god. Without taking that he created the earth at the very least we have a figure of power who speaks to people without being there, does really cool magic tricks, and gives people the ability to heal...