We say "seeing is believing", but God says "BELIEVING is seeing".  He wants us to live in faith, but that can be hard sometimes.  Especially when the dark clouds move in.  It's in the middle of the storm when holding on to faith is the most difficult.  When it seems like all hope is gone and our prayers have gone unheard.  This is when we need to stand firm like an oak tree in our faith, never lose hope, and believe.    

Faith is the substance of things hoped for and the substance of things unseen.