Words are part of what separates humankind from animals. Four-footed beasts don't build hospitals, schools, and churches, partly because they don't have the power of words. And, indeed, words are powerful. By words rulers are crowned or removed, nations are born or dissolved, and whole races are enslaved or set free. Words can guide us or deceive us, make us knowledgeable or ignorant, wise or foolish.
Words control our emotions.
They can make us restless or content, angry or peaceful, anxious or trusting, sad or joyful. Words can mean the difference between feelings of guilt and freedom, loneliness and acceptance, despair and hope. They can make us cry or laugh. Partly, we do. For instance, through words we exercise a great power over our fellow human beings.