How do we know about the past?
He was making the point about how do we know ANYTHING about the past?
Of course, you can find stuff about it. That is what archeologists do. But we know about the past by what people write about it, for instance, the Bible.
He then went on to say, for some reason a few centuries ago, the assumption was the Bible must be wrong unless there is evidence to say it is right.
He asked, does this really make sense?
He proposed a thought experiment: take a look at your house and imagine it is 2000-3000 years later. How much of your house is left? Factor in rain, wind, fires, earthquakes, floods, etc. Will someone be able to figure out much about your life from what's left?
Why should written information about the past be totally discounted in favor of artifacts from the past which are hard to come by for the difficulties highlighted by the thought experiment.
People make the assumption that the Bible must be wrong unless there is evidence to say it is right.
One could just as easily assume that the written record is reasonable accurate unless evidence says its wrong.
And indeed, to what extent is the Bible confirmed by archeological findings?
He cited a variety of findings that show the Bible is consistent with what is being found by archeologists.
So if someone is doubtful about the historicity of the Bible, walk them through this to get at their underlaying assumption about how do we know about the past and maybe they will think it over and give the Bible a fair shake. One can hope anyway!