Trial and error is the foundation of modern science. In Torah as well we must adopt an approach of trial and error to reach new horizons.
A Rabbi cannot make a correct legal decision until he first "stumbles over it," i.e., makes a mistake. Don't be afraid of making a mistake.
A Chassidic adage says: "not always can you pass over an iron bridge." We must precede and we must take chances along the way.
King David never walked on sure ground, he always felt in danger of fall. A tzadik said that till 40 he didn't know to what side he belonged.