Two question that a rationally thinking person ought to ask about the Bible, and any written document are: 1) Is what we have here, the same as what was written in the original manuscripts? Or was it changed along the line? 2) Even if it is the same – Is it true?
Lets start with question 1. Is it the same as the original, or has it changed?
Historians and archologists apply historiography and something called the bibliographical test.
The first question that they ask is: How long time is there between the original writing (the Autágrapha), and the oldest manuscripts that we have? The shorter the timespan, the more reliable. (Now Im not gonna go into the details of how you determine the age of a manuscript; but its not difficult. Historians can pretty easily determine how old a manuscrip is).