I found this on a few developer's blog, namely Ben Ramsey's, and it was powerful enough for me to do one.
I write code because its a passion for me. I write code because I believe one day I will enable someone, somewhere to get help for something they need. I believe that the code I write will give someone else the empowerment to get up and do something.
I work at a developer mentorship because I believe in the people who work there. I believe that empowering people to learn is what is going to change the world. I go to work everyday hoping that something I mention will cause someone to google it and learn more.