Think of "God's plan" as being like a computer program. Even if the "code" doesn't change, it can still yield different outcomes based on run-time inputs. Wheth

Think of "God's plan" as being like a computer program. Even if the "code" doesn't change, it can still yield different outcomes based on run-time inputs. Whether we pray, whether we repent, whether we even believe, etc. are such inputs. Free will says we can choose to do these things are not, but it doesn't mean there won't be divine response. At the very least, this is usually construed as affecting whether we go to heaven or hell. Depending on how far you take it, it can lead all the way to the "prosperity gospel" idea that shows of devotion can be directly tied to immediate and material reward. Prayer is the button that you push. It might have no effect, and whether it does or not might be preordained, but you still have to push it to find out.