Here are a few alternative thoughts:

(1) A prayer is a statement of a personal wish/hope/desire ... (internal mind-thinking).
(2) If the person doing the wish would also do something in behavior to lead toward the desired result, the wish might have a better statistical chance of success. And maybe not.
(3) People sometimes pray for bad results. Example: "I hope (pray) that the person who just dangerously passed me will end up in the ditch". And sometimes it seems that those prayers are answered ... (or maybe just bad luck for the other driver).
(4) What is different between hoping to a god and any other rambling internal thoughts which whiz through a human's brains all day long?
(5) Two people hope for opposite results? Which one would a (theoretical) god answer?