At various points in history, an eminently convenient and exploitable assumption.
History is not over yet.
Nor will it be after you and I are gone.
Without corroborating evidence, yes, it is safe to assume that the Bible and similar tracts are works of fiction. However, should you show me a magic beanstalk or an anthropomorphic pillar of salt, I might be forced to reevaluate my position.
History is not over yet.
Francis Fukuyama to the contrary notwithstanding.
Nor will it be after you and I are gone.
Yet Ted Holden's great great grandchildren will inevitably deconstruct works of pulp science fiction from the early 21st century, looking for evidence of cataclysms not otherwise supported in the scientific record.