I've been going through my manuscript, making line edits, and am surprised at how much tighter my prose has become since the first draft. It really shouldn't be surprising, but I am amazed that the words I'm reading actually came from my brain.
Line editing is essential to any polished manuscript. Despite what your subconscious is telling you, the words on the page are not perfect - or necessarily readable - the way they spewed out of your pen in the throes of passionate creative writing. Take a look at Stephen King's On Writing and you'll find that he has an entire section that shows his first draft complete with his line edits and reasons for why he made the changes he did.
I'll admit that when I first read that section about two years ago, I was sure that my work would never look that beaten up.
Surprise, surprise - my work was even more beaten up!
The goal of line editing is to say something in a simpler, more direct way that gets the point across without rambling or using huge words that don't need to be there. If I can combine two sentences into one shorter sentence without losing the message I need to get to the reader, I will.
Don't be afraid of this process. Treat your first draft like the rough shape of a clay sculpture. You get it roughly to where it needs to be, then you start trimming and shaping until that clay is a beautiful sculpture exactly the way you envisioned it. This process takes time. I already went through my manuscript once and line-edited the crap out of it. Now I'm going through it a second time on my Kindle, reading it paragraph by paragraph to catch any lingering issues. If you want more on that process, see my previous post here.
If you've made it this far, you owe it to your book and your future readers to pay close attention to each sentence and paragraph. As we all know, those sentences together make up the large tapestry of our story, and there's no room for a bad thread in such a large quilt!