Everyone and everything is created for a purpose. For the fig tree, its purpose is not just to appear beautiful. It is to bear figs. The Scriptures say the tree had no fruit, "...for it was not the season for figs." The idea is that the fruit was not quite ready to be harvested, or the fruit had already been harvested and there remained no more viable fruit (in violation of Hebrew law: to leave some of the crop/fruit for the sojourner or alien). Nevertheless, the purpose of the fig tree is to bear fruit. When Jesus sees no fruit, he curses the tree and, in a subsequent passage, we know the tree withered to the roots.
When we don't serve our purpose, we are as good as dead. That is, we are ineffective and inefficient. You remember the old adage, "Dead men tell no tales." In the same way, "Dead trees bear no fruit." Here are some points to ponder about serving your purpose and bearing fruit in life -
1.) God created you and gave you a specific purpose in this life. Your purpose is to know God through a relationship with Christ. Your responsibility is discover how to use your time, talents and abilities to glorify Him.
2.) When you discover how to use your time, talents and abilities in bringing glory to God, you are getting past appearances (the fig tree - only leaves) and bearing fruit. These fruit will come as a result of your relationship to God through Christ. Without Christ and His Lordship over your life, all your works will only contribute to appearances, not real fruit.
3.) The "fruit" of your life can be summed up like this - When you use your time, talents and abilities, are you pointing people toward Christ or bringing attention to yourself? Does God get the glory for the spiritual "fruit" or are you bringing glory to yourself and your service?
"I believe God made me for a purpose, but He made me fast. When I run, I feel His pleasure."
-Eric Liddell "Chariots of Fire"