Like your style, disagree with the content.
Desire is more decisive and conscious, it's more specific and directed. Passion is more natural, spontaneous, wilder and it ignites imagination. Passion can sprital out of control, but so can desire. In fact, when you desire something that may bring you down you're less aware of it than you would be if passion pushed you there instead.
Passion provides identity. Desire shapes it.
I could write a thousand words as it's a beautiful topic indeed, but maybe I can sum it up in a few more words:
Desire without passion is weak.
Passion without desire is futile.