The vision is projecting you into the future, whereas mission anchors you into the present.
I get almost all my clients through the process of setting their business vision and mission. And though most of them consider it a "corporate thing to do", at the end of the process they truly understand the value it brings.
I believe a true entrepreneur should have the ability to propel his business into the future and to make out a vision for it. That's one of the main things that differentiate an entrepreneur and an employee.
But vision is the most important as it is like the light at the end of the tunnel: it gives you meaning, direction and a scope. It is the full purpose of your organization. It allows you to focus on what really matters and it offers you clarity for decisions.
Here are some questions to ask yourself when searching for THE vision: