Hi I am in a dilemma, Should I save my rebate check or should I spend it?

I am 23, and a student of University Nevada Reno. I just recieved my rebate check of 600 dollers from the government today and put it into saveings. I think it is wiser to save the money in case of emergencys or if I lose my job too a poor econemy but my friends tell me to spend it in order to help the econemy. Should I save my rebate check or should I use it to better the econemy by spending it?