To Succeed, Persevere
Of one thing you can be certain: your work will never be published if it remains tucked away in a drawer. You need to submit your work for it to see the light of day and be read by others. While this means you will receive rejections and sometimes even reach the point of putting a particular project aside, you need to persevere if you want to be published.
To do this, keep two thoughts in mind. First, rejection is very subjective and many times has nothing to do with the quality of your work. An editor may actually love what you submitted but it's just not right for her or at least not at that particular time.
Second, rejection has been endured by every writer — even the best:
Robert Pirsig received 121 rejections before Zen and the Art of Motorcycle Maintenance was published, which went on to become a highly acclaimed classic and bestseller.
The first Chicken Soup book was self-published because no publisher wanted the manuscript.
William Saroyan claims to have had a stack of rejection slips three inches high before his first acceptance.
Jack Kerouac's On the Road traveled among publishing houses for six years before it was accepted for publication.
Ulysses, considered the best novel in the English language published in the twentieth century, was left in limbo by the publisher for nine years until James Joyce sued to force publication.