Fear, when one looks at it closely, comes from not being free.
You have done something wrong in the past. The thought of being found out some day is fear. Then the facade you have built around you with all your contrivance will come crumbling down. You don't want the real you to be seen by the world in full nakedness.
Fear is also in the thought of what is going to happen tomorrow. How do you forge ahead, become rich, powerful, famous, admired by those around you, envied for your never-ending success. Thought of never-ending success carries in it the never-ending fear of failure.
Can one be free of all these? Are you not curious to know how it will be when that happens?