I believe that rejection is actually encouraging. It signals that someone took the time to read your work, and offer you feedback. The challenge is learning from the rejection. If you consistently receive the same comments (i.e. POV is inconsistent) then learn from your mistake. Get your hands on a great writing instruction book, and try to improve your craft.
Another way to grow as a writer is to join a critique group. Honest feedback on your work is a tremendous help, and stretches your ability as a writer.
Whatever you do, don't stop writing. When you receive that rejection...and you will, have your moment of disappointment, learn from your mistakes, revise your manuscript, and send it out to another agent or editor. I also try to remember this quote from author James Scott Bell, "Rejection isn't personal unless it's accompanied by a punch in the nose."