But the fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control. Against such things there is no law. Galatians 5:22-23 (NIV)
There are two huge things that the Fruits of the Spirit accomplish here on Earth. They give you the power to fulfill your destiny in Christ. Without the Holy Spirit bearing spiritual fruit inside of you, you would be powerless. You wouldn't have the endurance and faithfulness to complete the calling that God has given you. You wouldn't even have the self-discipline to study your Bible or pray. Without the Fruits of the Spirit, the gifts that God has hidden inside of you, would stay locked away forever.
They are what God uses to draw people to Himself through you. Do you know anyone who, no matter the situation, always radiates a godly peace - They are unshakable. People in this world are drawn to that kind of peace. With all of the chaos surrounding them every day, they search their entire lives for whatever peace and joy they can get their hands on. They end up trying to fill the void with fleeting counterfeits like alcohol and illicit sex. Things that merely numb their pain for a short while, but leave them longing once again, after the party is over. When they look at you in a time of crisis, and see God's unshakable peace and joy staring back at them through your eyes, they want to know what you know. Then, you can introduce them to Who you know.
Likewise every good tree bears good fruit, but a bad tree bears bad fruit. 18A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. 19Every tree that does not bear good fruit is cut down and thrown into the fire. 20Thus, by their fruit you will recognize them. Matthew 7:17-20 (NIV)
Jesus told His disciples that you can tell if someone truly belongs to Him by the kind of spiritual fruit that they produce. What does that mean? When you surrender your life to Jesus, your salvation is not free. It's bought with a very high price. The crucifixion and death of Christ. You may sometimes ask yourself why God thinks you're worth that sacrifice? Despite all of your attempts at perfection, you constantly miss the mark. Surely trading Jesus' excellence for your mediocrity could not have been the best choice. But Your Heavenly Father has a very special kind of love towards you. He longs for you to be able to bask in His presence.
And, once He finally gets you - You're Marked. Now, the changes don't happen over night. They're gradual. You may not notice them over days and weeks. Or even after several months. But, you are God's work in progress. And, eventually, the signs that you are His become more and more evident. Everything that you do. Everything that you say. You begin to look more like Jesus.