I always had my reservations about the somewhat submissive nature many of our religions have vis-a-vis God, i.e. the "Thy Will be Done" prayer or the Muslim version Inchallah (God willing). It is hard to be a creator of your destiny if everything that happens is by definition an act of God. On the other hand, I also struggle with the popular new movement, "The Power of Intention". We pretty much will ourselves along a path, be it spiritual or not, and risk deviating on a big ego trip. If you use the Power of Intention, aren't you implying the path you are on is sub-optimal. Is it the you or the You who makes this assertion?
With these reservations in mind, I nevertheless invoked the "Secret" on a recent business trip in Paris a few times. To circumvent the usual traffic chaos over there, I had to mentally move traffic conditions over there just to make my appointments. Of course it worked, and I justified my somewhat narrow-minded agenda by saying that I had promised to meet these people, and a promise cannot be broken. Now I am wondering if God was laughing in the background, " You fool, you have the power to reunite with me now, and you use your power for running a glorified taxi service".
As always, the truth lies probably in the middle. My favorite prayer is "True Self, May thy Will be Done. When I invoke this prayer, everything that happens to me today is optimal for my spiritual development. If your True Self tells you to move mountains, then so be it. True Self, May Thy Will be Done!