Reading is vital to a writer's soul.
Why? Great question. Here we go...
#1. Reading hones your craft.
Seeing how others structure their sentences, weave their plot lines, or develop characters presents a model (an obviously winning one since you're reading a published book). Read and study the big name authors that are out there, those who have mastered the craft.
#2. Reading outside your chosen genre stretches your writing capabilities.
I don't write young adult but I read it because of its snappy dialogue. I don't write horror but sometimes I pick up a tastefully done creeper because of it's shock-and-awe factor. I don't write epic sagas but sometimes I'll page through one to fill up my beautiful prose tank. Then I can use all these elements in my historical fiction to make it a more full-bodied manuscript.
#3. Reading puts your mindset into a different world, allowing you to see your created writerly world with fresh eyes when you come back to it.
Sometimes when you're stuck on a particular scene, it helps to walk away from it for a time and focus on something else.
I like what Jeff Goins had to say recently about reading...
"Read widely. This isn’t just research, it’s practice. Honing your craft. Studying the masters who came before. Pick a book or two that didn’t just pop up on your Amazon referrals list; read a classic or something that has absolutely nothing to do with your chosen field. We base our careers on words, so the best thing you can do is absorb as many of them as possible from as many different sources as you can."
So, go ahead. Toodle over to the library and pick up a few novels, but don't look for me there. I've got enough on my TBR pile right here at home.