I know answering a question with a question is not always helpful, but the query begs a list of qualifiers:
Are you good enough for what?
Good enough to make time for your writing?
Good enough to put the right words together to evoke just the right emotion?
Good enough to come up with a compelling plot, engaging characters, a deeper meaning?
Good enough to finish what you started?
Good enough to find the right agents to query, land an agent, land a publisher?
Good enough to deserve a fair advance or, better, a great one?
Good enough for the story to garner good / great reviews?
Good enough to find a readership, be invited to the Oprah show, make a best seller list?
Good enough to make money with your writing, earn a Pulitzer Prize, Nobel Prize?
Good enough to write another story?
Good enough to finish that story?
The question speaks to a fear buried much deeper than the words themselves.
Writing, like every other endeavor, is an outer activity which affords the opportunity to learn more about your inner self. As most of you know, in my down-time when not consulting with writers on their plots, I use what I know about plot and the universal story form to delve deeper than the words themselves.
At that level, the question indicates that the writer is becoming overwhelmed by the external demands of writing, enough so, she is losing her passion for the writing itself.
Rather than carry the pain of all the hundreds of things that can interfere with your writing life, focus your attention instead on the one thing you can do right now in this moment.
Trust that if you are called to write there is a reason for it.