You ---"I guess the fact that every scientific study of prayer concludes that it does not work."
Me --- "You denied the existence of any study showing the efficacy of prayer "
Every means all. Which means the opposing population is empty.
You need glasses.
Do you know what a 'guess' is? It is a guess. It is not a statement of fact. But so far, you have only brought forth one unauthorized, unscientific study whose authors won't respond to phone calls and one is even indicted by the FBI, for fraud, I think.