I attend a church that believes, and I believe myself, that prayer actually causes things to happen, not by making God do something or by changing Him, but by giving Him free rein to act in a realm where mankind has been given authority (Luke 10:19) and dominion (Genesis 1:26). Anyway, we believe that Christians can pray for sick people and God will heal them. Lately, though, something has been eating at me a little bit. I hear things in people's prayers like describing to God what He needs to do ("God, just open those arteries and clean them out, flush the crud out that's clogging them up, cause the blood to flow freely!" "Lord, just make that cold go away, clear out the phlegm and inflammation, cause that cold bug to just die!" etc.) It's almost like we think God doesn't really know what's wrong with the person's body... like he's a first-year med student who needs a guidebook or something. Even worse, I hear phrases like "from the top of her head to the soles of her feet" that really add nothing to the prayer but words. And then I think about Matthew 6:7-8 and wonder if we are not sometimes in danger of going where those Gentiles of yesteryear went.
I guess in a sense we pray hoping to build up the faith of the person we are praying for... intending somehow to show that we empathize with them. Or maybe we have heard prayers like that which contained genuine words of prophetic knowledge from God where the person praying speaks details he could not possibly know without a word from the Holy Spirit, and we subconsciously try to emulate that. Or, sadly, maybe we as the praying persons are trying to kind of rev ourselves up so we feel like our prayers are getting traction somehow. I don't know why the tendency is there... I've fallen victim to it myself... but it seems to me that the work is God's and the faith is ours. A prayer of "God, heal him!" that has behind it the understanding and faith that God can and wants to heal that person, likely will work better than all the top of the heads and soles of feet we can muster.