The Holy Spirit is described generally as the power of God, which is certainly correct, but power comes in a number of forms. There is a flowing power caused by the movement of an object. Thus God uses water to illustrate an aspect of the Holy Spirit (John 7:37-39). There is healing and nourishing power, so God uses oil to symbolize His Spirit. Words, symbols we use to represent ideas, the raw material of our thoughts, have awesome power to influence. Thus God says through Jesus that His words "are spirit, and they are life" (John 6:63).
Words give us the power to communicate ideas from one mind to another or to many minds. They carry the power to instruct, encourage, discourage, mollify, anger, vilify, inspire, exhilarate, create, or destroy. They can make a person change his mind, motivate him to stop or move, do, undo, or redo. The power of words is almost limitless.
If we examine the fruit of the Spirit, we find that they all have something to do with our minds. Words are a large portion of the mind's working material and therefore play a huge role in what the person produces with his life. It is no coincidence that Jesus is the Word of God, and the Bible, the written revelation of God and His purpose, is also the Word of God! God is trying to tell us something. He is concerned about our minds because what goes into them will determine what we produce with our lives. Will it be fruit leading to eternal life or fruit leading to death?