We need faith when exploring the unknown.  Our curiosity alone propels us into new situations.  Faith is the willingness to take a risk in the advancement of knowledge.  

In Lava Beds National Monument, in Northern California, lies a shield volcano.    There is no obvious cone, but lava tubes radiate outward for many miles.  In places the lava tubes have caved in producing hundreds of individual lava tube caves.  Standing at the entrance of one of these caves, I noticed just how little I could see beyond a few feet.  In my mind I thought of bears or mountain lions or bats or snakes or spiders that might take up residence in such a cave.  But my curiosity overcame my fear and I took a couple of steps inside.  Looking back, I could see with perfect clarity the opening of the cave, but looking forward I could see very little.  It was pitch black.  I took a few more steps.  As I went deeper into the cave, it was always the same; I could see only the path from the entrance, and not the path ahead.  I had to step into the darkness before I could see what was there.  

In a similar way, in order to test God, one must do as he asks.  Only then will we know where we are being led.