I think the gospels and letters are not fiction because they were written within the lifetime of those who would have witnessed the actual events (and in some cases witnessed the actual events: John, Peter, James). The authors and early church believed what they preached even if that meant adversity. The church grew between the time of Christ and the first appearances of the epistles. Alternatively, there was every reason to let things die down after Jesus' death if the events were not other than what was related.
If the events of the NT were not true, I do not think there is ground for positing an "honest mistake". I think the only logical alternative is a conspiracy. No one has yet to give me good reasons why this might be the case.
If the events of the NT were not true, I do not think there is ground for positing an "honest mistake". I think the only logical alternative is a conspiracy. No one has yet to give me good reasons why this might be the case.