Creationist-explain this!?

How do we know that the text used to write the bible are correct and from the same time period? We know through radioactive dating-Which is the same way we know that the Earth is 4.6 billion years old. So, if you can accept that your texts are from the time period in which is needed for it to be scripture, why can't you accept the Earth is 4.6 billion years old?!