If you ask me... passion helps to motivate you to keep doing what you're doing. Like how an artist can go on painting even when they know it may not be profitable for them... or how a baker can bake and bake for years in his bakery without getting bored. However, it won't be a good 'starter' - to take action - in the first place. And passion, like a flame, can dwindle over time and may extinguished one day.
In my opinion, what truly motivates people to take action in the first place is either anger or desperation.
When one is in a desperate situation (poverty, brink of bankrupt, brink of losing his job), he is willing to take action to salvage his situation. Or when one is angry (being mocked at, looked down by others, unhappy with his/her current status), he/she takes action to prove to them. That's why those who are in a comfortable lifestyle (even if it is a low paying job, but he/she is contend about it) will never seek out to improve their status.
Keep in mind that's just my opinion though.
I personally use anger to make me take action. And when I see results, I treat the results as motivation to keep going.
And I believe emotions do come to play. When you see results, you feel accomplishment and that's what keeps me going. And bringing back the example at the start of my post, an artist feels satisfaction when he/she receives compliment for his work... that rekindles his/her passion or to continue doing it. But what if he/she gets criticised about it? Or when no one seems to appreciate his/her work? Or a baker whom bakes dozens of cakes and loaves of breads for years but never seem to get appreciated for his/her work (however, if it is for income, then that's a different story because they are 'forced' to continue doing it). That's pretty much like a douse of water in his flames of passion.... sooner or later, he/she will just give up and move on. Hence, passion may be due to emotional rewards. When you see those skinny guys hit the gym initially, they don't like it. But when they start seeing results they continue doing it... and these people will start going to facebook posting images like "GYM IS MY PASSION" and stuff. But were these guys ever had working out as a passion in the first place? I doubt so... I believe what made them hit the gym in the first place was being ridiculed for being skinny, or hate their body image and just wants to improve it to have a better chance of getting a girl.
Just like relationships... at the start, a relationship is full of passion and love, because both lovers are excited and always try to keep the other happy... but over time, when one of the partner takes the other for granted, they don't feel appreciated anymore... that's when the love begins to die out. The passion and romance in the relationship withers like flowers and decays.
LASTLY, AND AGAIN, this is my humble opinion. Nah, whatever, back to my glass of champagne.
)
