Many of the areas of my life that I have had success, were the times when I felt afraid and continued anyways. When I was younger, I naively thought that fear was simply something to overcome and it was more important to take risks and ignore fear. Now that I am a little older, I realize that fear can be good or bad, just like everything else in life. It depends on the situation and it is best to know yourself in order to determine how to address fear.
Fear can be a great motivator. If you suddenly find that you are at risk for a heart attack, the fear of dying might be enough to get you to a gym to finally take control of your health.
Fear can stop you from doing something stupid. When I was younger and felt invincible, I could have benefited from understanding that sometimes fear is your body telling you that jumping off the roof into a pool is stupid idea!
Fear can also prevent you from reaching your potential. A fear of failure can stop you from pursuing your dream of owning a business, investing in a great company, or getting onstage to perform. If you have a goal but feel afraid, determine why you are afraid. If you want something bad enough, the fear of failure won't be powerful enough to get you to quit before you even begin. Many times it took me pursuing something to realize that the risk of failure is often built up in my head and that it really wasn't that bad.
Understand how fear affects you to know the difference between positive change because of fear and limitations because of a fear of failure. Continue to push towards the accomplishment of goals and build systems that help you to move confidently in the direction that you feel you should go.