Can we be certain what the Bible means?

Sipech has written an interesting and thoughtful piece on Uncertainty over on his blog, The Alethiophile. Go and read it, then come back for my thoughts.
I largely agree with what he says. It's important to acknowledge what we can and can't be certain about, and to be humble about our own interpretations.
But I disagree that the limitations of our own understanding mean that we can't know or be certain about much of what the Bible says. As G K Chesterton said:

What we suffer from to-day is humil...