Lane Wallace, who’s writing a book on passion, finds that it starts with a vision:

And the origins of passion, I’ve concluded, are directly linked to this idea of ‘vision.’ For passion to take hold, we first have to have a vision of an alternate future that ignites a fire within us: a vision of a wrong righted, a community developed, a great new product made and sold, a goal achieved, or just a new relationship full of happiness and bliss. Not every vision leads to a passionate pursuit of it, of course. But in all cases where people do pursue something with passion, it’s because there was a vision, first, that sparked an unquenchable flame and desire to make that vision real.

It’s easy for me to be cynical when people start talking about vision, but I’ve never seen a team (or a person) succeed at anything difficult without one. The responsible business person in me would add that once you have a vision and you’ve decided to work toward it, you need to set measurable long term and short term goals to make progress toward that vision.