Late one evening, Thomas Edison was coming out of his laboratory.  He had been working all day and into the night trying to uncover the secret that would help him invent the light bulb, but to no avail.  In fact, he had been working for months and months on that project, but with no apparent success.  As Edison came out of his lab, he looked exhausted, and a friend met him there, asking, "How many experiments have you done already?" 

Edison replied, "Over 1900." 

"Over 1900," exclaimed the colleague.  "That's incredible.  You must feel very disappointed by now - very much like a failure." 

Edison straightened up to his full stature and his eyes glistened. "Not at all," he said. "I don't feel like a failure. I've made so much progress.  You see I now know over 1900 things that won't work.  One of these days I'm going to hit on the one that does." 

That's what it means to live with persistence and expectation.  At least in part, it's also what it means to live by faith.