In think prays work in two ways: you may have the luck that your prays come true or you believe them so much and you want them so much that eventualy they come true.
I don't believe that prays really help, I mean, I don't believe there's someone looking at you and hearing your prays. I mean, if there was a god like that you wouldn't need to pray. For me it sounds like a feeding to the lord's ego. If he was caring and nice he would look to your suffering and he would help you without you to ask something or give anything.
Even so, believing is good for the soul and for the spirit. I'm in medical school, and one thing that sometimes we have to ask, is the person religion, because among other things, it can help us to give strenght to that person.
I grew up in a very religious family, even so my father is not religious. So I grew up hearing the two sides of the story and chosing my one. I know a lot of pray, I used them sometimes, but they only work if what you ask was suposed to work.
I mean, I was once stupid enough (at my 12) to walk for hours on my knees while praying, and the ground was rough. So it hurted, my mother lighted lots of candles for me, in my country biggest santuary, and what? Really, this situations make me laugh because, they are so ridiculous. But it didn't help at all, here I am, 10 years later still struggling.