Until God opens the next door, praise him in the hallway. I think this quote is just a cliche and doesn't mean much to anyone until they find themselves in a hallway and see how difficult it can be to trust and praise God in times of waiting.
One of my favorite inspirational quotes: The broken will always be able to love harder than most. Once you've been in the dark, you learn to appreciate everything that shines. So much wisdom in two little sentences.