You will be rejected. Everything you create is not a masterpiece that will easily rank up there with Harry Potter and Lord of the Rings. It's going to hurt, but in the end, good will come out of it. Here are some ways you can get through those rough spots.
1. Realize that God doesn't want your book published at this very moment. I know this might be hard to understand, but the publishing industry isn't as fast as those blog posts made it seem. It's also very competitive and difficult to "make it".
2. Rejection doesn't always mean that your book isn't good enough. One publisher rejected me because my book was more Christian than general market. But they did compliment my story. So it wasn't because I wasn't good enough.
3. If the editor or agent recommended specific revisions, listen to them. They're the professionals.
4. Realize that you aren't The Exception. I used to think that I could blast through the publishing process because how on earth could someone turn down my amazing, trendy idea? Plus, my grandfather could blast email everyone he knows, telling them about my Great American Novel. No, that is not how the industry is. Even J.K. Rowling was rejected 12 times before a publisher acquired Harry Potter.
5. Don't immediately self-publish. I greatly admire people who self-publish their novels. There is nothing wrong with it...if they do it purposefully if they decide that self-publishing is truly the path they want to take, not because a publisher rejected them for a legitimate reason. When I attended Realm Makers this summer, I heard a great piece of advice. Someone suggested that someone who wants to self-publish should submit to publishers. What the publishers say about it should determine whether or not the book is ready for publication.
6. Keep praying. I pray every day that God will guide my journey towards publication. I want my book to impact peoples' lives, and only He can direct that.