Why do you need to have burning desire?

Burning desire to be or do something gives us staying power--a reason to get up every morning or to pick ourselves up and start in again after a disappointment.When you want a thing deeply, earnestly and intensely, this feeling of desire reinforces your will and arouses in you the determination to work for the desired object. When you have a distinct purpose in view, your work becomes of absorbing interest. You bend your best powers to it; you give it concentrated attention; you think of little else than the realization of this purpose; your will is stimulated into unusual activity, and as a consequence you do your work with an increasing sense of power.Happiness can be defined, in part at least, as the fruit of the desire and ability to sacrifice what we want now for what we want eventually.
Behind every desire is a deeper desire. Behind the deepest of desires, you'll find the true identity of the person you are.
If you follow only the desires on the surface, without ever looking beneath them, you'll likely come up empty. For knowing why is a key part of accomplishment. If your desires are ever to be realized, you must question them. Know that beneath each and every desire is a more profound, more fundamental purpose.
Perhaps you are a slave to your desires, or perhaps you are shocked by your desires, and maybe you're even fearful of them. Have you ever considered stepping back and really examining them? They all exist for a reason. Knowing and following those reasons can lead you to an undeniable sense of real and lasting fulfillment.
Behind your desires you'll find something even more compelling -- purpose. The more often you bring that purpose to the surface, the more successfully your life will proceed