I've been browsing the "World Question Centre" at edge.org, the website for thinking folk with time on their hands. The 2005 Edgequestion is a good one: "What do you believe is true even though you cannot prove it?"
...Ian McEwan" makes a telling point. "What I believe but cannot prove," he says, "is that no part of my consciousness will survive my death." His enlightened fellow Edge contributors will take this as a given, but they may not appreciate its significance, which is that belief in an afterlife "divides the world crucially, and much damage has been done to thought as well as to persons by those who are certain that there is a life, a better, more important life, elsewhere." The natural gift of consciousness should be treasured all the more for its transience.