How do we believe?  Two ways.  We either believe by considering and affirming which rings most true to what we already believe, or we believe by considering which seems most consistent with how we understand reality.  Either way, however, we encounter a problem:  we may never believe anything other than what follows from what we have always believed.  We may never step outside what we had already decided is real and true.  We may never invest in mystery and the unknown.
     This we cannot do.  Think about all the discoveries that have been made, think about all the great lands that have been found.  Would any of these been made or found if people had not been willing to step outside of what they had always believed to be true?  Sure, these people stepped out on the basis of what they knew.  But they also knew they didn't know everything they wanted to.  But they stepped out anyway.  They invested in the unknown.
     As must we all.  No one has ever found what is most important by sticking to what she has always known.
     Take a step into the mystery, walk into the unknown.  Live by faith, faith in a God without whom mystery would be forever unknown.