In the writing process there are two stepping stones to get across the river of success.
The first stone is what many call "writing." It is the act of putting words to page. It is the act of crafting something. Many writers would prefer to step on this stone and then leap across the river. But when they land, they sink into the mud, creating a mess, and going nowhere further.
The second stone is editing. It is the act of refining. The writers who step on this stone are able to make a graceful departure onto the river's opposite bank and just keep going.
Here are three specific reasons why editing helps writers keep going toward success instead of sinking down in the mud.
1. Editing makes your work shiny for the publishers', reviewers', and editors' eyes. Thoroughly edited writing attracts the eye, helping you get noticed.
2. Editing makes your work flow. Editing shows the shallow points of a character. It shows plot holes. And unless a mistake is shown and recognized, it cannot be fixed.
3. Editing teaches you. I know from experience that I learn from editorial comments. When I correct mistakes that editing has found, I learn not to make those mistakes again. The less mistakes made in the initial writing process, the easier editing is. But, I will warn you, editing never becomes unnecessary.