"Let me give an example of the problem. Not long ago, I was invited to participate in a debate on religion with a born-again Christian. I was told that we could debate any aspect of religion, so long as we agreed that the Bible was the source of all facts."
  This from the editorial in todays paper "Campus should allow opposition....."

If I'm not mistaken you would agree with the terms of this debate, that the Bible is the source of all facts?   (Had to look up presuppositionalist for myself).

People are free to make decisions that lead to their happiness.   For some, certainty is required to be happy.  For others, like me, curiosity never stops and I'm fine knowing I can't know all things.   Both types can live a life of compassion and love.  Both can also turn people to intolerance and hate.    We make an emotional/intuitive choice, even if we wrap it in intellectual argument.