The U.S. Conference of Catholic Bishops was the object of a rather smarmy post on James Randi's website recently. In brief, the USCCB stated that it is inappropraite for Catholic institutions or individuals to promote reiki. James Randi suggested that the same should hold for prayer.
This argument would hold quite a lot of water if prayer had the same aim as reiki. My problem - my fear - is that most Christians have no idea that it doesn't.
What is the purpose of prayer?
Is it to get what you want? To make you feel better? To balance cosmic energy?
No. It's goal is the giving of due worship to God, our Creator. That is not scientifically testable not because it doesn't "work" but because there is no claim that it does anything on this earth. There is not claim, and no requirement, that prayer do anything to the pray-er. Our prayer does not cause healing or anything else. The words we think or say are not a magic spell.
God cannot be coerced or forced. We do not earn or cause anything by our prayer.
Does that mean I never ask for anything? No, of course not. If we are truly children - God's children - then we have to allow for childlike crying out. We do ask for things in prayer. We do try to make deals, to tell God what we want, what we'll "give Him" in exchange. But does it really do anything?
No. Not because prayer doesn't "work" but because that's not what prayer is. Prayer is not a seat at the negotiating table. Prayer is not the opening of a spellbook. Prayer is not the payment of a fee for service.
If you want worship God, pray. That is the work of prayer.