This should probably go in the history thread but I think you're being very unfair to Herodotus and Thucydides: unlike the authors of the Gospels, who were writing with a religious purpose, they were actually trying to write history, whatever flaws might be present in their methodology and their finished work, and in fact might be said to have invented the very concept of history, as pretty much everything up to then had been either straight, bare-bones chronology ("In the 3rd year of King So-and-so's reign, he defeated the Xians and built the great temple of Such-and-such") or blatant propaganda, painting every conflict as good guys (us) vs bad guys (them).

Herodotus's History was a huge step forward from all this. He tried to do research, travelling when he could to the places involved and talking to the locals, listening their stories: this in itself was a new idea: he consistently reported several different conflicting accounts of the same events when he thought there was no strong basis for choosing one over the others - another new idea, as opposed to just picking the version that best fit the writer's propagandistic purposes and embellishing it even further. He also quite often gave a rational alternative to explanations that resorted to the supernatural (read the anecdote about the fish again). And though he certainly was writing as a Greek who was naturally in favour of Greece retaining its freedom from the Persian Empire, he did NOT paint the Persian Wars as a battle of good vs evil (unlike Frank Miller) - if he didn't achieve absolutely perfect objectivity, the very idea of even trying to do this was yet another unprecedented conceptual leap. If you haven't read his History for some time I think you should give it another look.