Scientifically speaking, it has been shown that prayer does not work (source of one example, source of second example). Even with that determined, that still leaves open the possibility that prayer might have the power as positive affirmations might have, e.g. that even though praying for something to happen does not make it more likely to happen the act of praying itself may make the person praying feel good about themselves or otherwise have a non-supernatural effect on the person praying. If this is true, I imagine it would be easy to find evidence of such a thing. Do you have any credible sources supporting the existence of such an effect? If causality cannot be shown, is there even evidence of a mere correlation between praying and future mental health or personal success?

Pel wrote:Also doing good for [an allegedly existing] Gods sake, not just for the sake of other living beings on earth is I believe beneficial.

This statement appears to me to be a meaningless tautology: Doing good is good.

I think it is possible that prayer may have a subjectively good placebo effect for the prayer, sure. Surprisingly, though, the scientific studies to which I linked in my previous post showed that people who knew they were being prayed for had worse outcomes than those who did not know they were being prayed for or were not being prayed for. I would still assume that is a placebo effect, but it is a negative one rather than positive which is remarkable.