I've been having trouble lately defending the practice of praying for those who are sick. Praying that those who are ill and their loved ones would accept God's will, whatever that may be—that type of prayer makes sense to me. But doesn't praying for someone's healing imply that we have some control over God's will? If God felt it was time to bring a sick person home to him, would everyone's prayers for healing somehow change God's mind, as if what we wanted was better for the world than God's plan? And if prayer can accomplish that, it seems unfair to the sick person who has no one to pray for him.
Do you think that those people who asked Jesus to heal them in the Gospels should have kept quiet? If Jesus wanted to heal them, he would know their need and respond if he chose to. But the fact is that Jesus told us to ask for what we need (cf. Mk 11:24, Lk 18:1). He obviously wanted those people to express their confidence in his power and love. So it is with us. It is not a matter of trying to change God’s mind. God may very well intend to heal certain sick persons if they ask him to. The prayer of petition requires faith. It is good for us, and he always wants what is good for us.