A writer reports on the universe. When he presents his credentials, the gates of heaven and hell are equally opened to him. He can hear the devil’s defense and god’s accusations. The guards at the king’s heart let him in. The writer can be anything and any one he wants. When he writes he is a god, he creates.
I never had any doubts about my abilities. I knew I could write. I just had to figure out how to eat while doing this. [Cormac McCarthy's Venomous Fiction, New York Times, April 19, 1992]
If you are destined to become a writer, you can't help it. If you can help it, you aren't destined to become a writer. The frustrations and disappointments, not even to mention the unspeakable loneliness, are too unbearable for anyone who doesn't have a deep sense of being unable to avoid writing.