If the Earth is only a few thousand years old, wouldn't that mean man roamed the Earth at the same time as all the dinosaurs - even the meat-eating ones? Man and dinosaur bones have been found in the same areas. Tough to believe T-Rex and man could coexist peacefully, especially given their vastly different dietary and environmental needs.
As for "satan planting the bones to test our faith," well, one could use that argument against anything. Problem is, if we're just going to dismiss anything that contradicts the church as evil magic, why bother doing any research or expanding our scientific knowledge at all?
