makes a good point about prayer--it can have a strong placebo effect. Anytime you believe or reinforce your belief with some action, your attitude and determination are effected. It like the story of 'The Little Engine That Could
', who, while saying "I think I can. I think I can," was able to pull a train over a mountain. The lesson was clear: think positive and be optimistic and you'll get further. Prayer can help from this positive mindset--but the point I was trying to make is prayer can also be detrimental. If one relies on prayer alone, the effects can be quite bad if not dangerous.
There are other ways to gain a positive mindset besides fooling yourself with prayer. For example, studying for a test has two benefits: you review information pertinent to the test (hopefully) and build your own self-confidence in your abilities to take the test. Eating a healthy meal before taking the test. Gives you healthy nourishment, gives you the feeling you've done some more preparation and, if you're like me, you feel good after eating something good for you.
In general, any ritual that is done with the idea that some desired effect will result will generate a placebo effect. I once tutored a lady in algebra who didn't want to take her exam without having her "lucky bookmark". I knew from tutoring her that she knew the material well enough to do fine on the exam, but if having her charm makes her feel more mentally prepared, then fine. What I would advise against is not taking the test because she didn't have her charm, or not studying because she did. If prayer for you is the spoon full of sugar that helps pallet the proven medicine, or the pat on the back that gives you the confidence to take on a tough task, or if prayer is your way of verbally working through a problem; do it--but don't use it exclusively as a means to an end.
Anyway, I appreciate your comments Hiep Nguyen and I hope I don't scare you away like I did poor Lisa Marie.