Put simply, they lied a lot. Let's first take a look at how some of these conclusions are reached, then consider the implications of these conclusions, if they be true. I believe that the Bible as we have it today can not be refuted on its own merits because there are no inconsistencies within it. To discredit the Bible, one must depend upon misinformation and assumptions. In past articles, we have noted some glaring examples of misinformation.
Assumptions are a little different.
An assumption, or premise, may be true or not true. But any conclusion that is based on an assumption can only be as true as the original assumption. In the first place, this is more a conclusion than a premise. If one begins with the conclusion that the gospels are not to be considered as historical documents, then it is predetermined that all other documents carry more weight than the gospels. This means that when there is a conflict, the gospel accounts are trashed in favor of the other accounts.