Socrates said, "The misuse of language induces evil in the soul." He wasn't talking about grammar. To misuse language is to use it the way politicians and advertisers do, for profit, without taking responsibility for what the words mean. Language used as a means to get power or make money goes wrong: it lies. Language used as an end in itself, to sing a poem or tell a story, goes right, goes towards the truth.
A writer is a person who cares what words mean, what they say, how they say it. Writers know words are their way towards truth and freedom, and so they use them with care, with thought, with fear, with delight. By using words well they strengthen their souls. Story-tellers and poets spend their lives learning that skill and art of using words well. And their words make the souls of their readers stronger, brighter, deeper.