My friends: I myself feel sure that you are full of goodness, that you have all knowledge, and that you are able to teach one another. (Romans 15:14 GNT)
The Fruit of the Spirit is GOODNESS.
Galatians 5:22-23 says, "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."
Our God is good. Therefore, goodness is the nature and character of God. It makes perfect sense that one of the Fruits of the Spirit is goodness.
Goodness begins with a love relationship with God. It is through His power that we can demonstrate goodness. Why does God want us to demonstrate goodness? We are to be a light showing what is truly moral - the beneficial commandments and righteousness of God.
Goodness is acting like Jesus. It is choosing good over evil and doing things that help others, whether or not they deserve it.
"If a thing is free to be good it is also free to be bad. And free will is what has made evil possible. Why, then, did God give them free will? Because free will, though it makes evil possible, is also the only thing that makes possible any love or goodness or joy worth having." - C.S. Lewis