I have heard two different people in the past week emphasize the power of prayer. One of the people said something along the lines of "when people pray, things start happening" the other something like "if all the people in [some town--or it may have just been a church] prayed, [said town] would be changed," but it's sort of like... well, yeah, people praying is quite a change, but it isn't the cause of the change, it's an effect. God is the cause of the change, and the further changes might not be along the lines that those people are praying. On the one hand, yes, God hears us when we pray, but on the other hand, while the emphasizing was not in a trivial context, I fear a vending machine god. It seems important to keep the power of prayer as derived from the power of God, and then to keep the fear of God in view.
The Fear of God, so far as I can tell, arises from the acknowledgement that God can do whatever he likes. God is good, yes, but we must be humble and acknowledge that what good may turn out to be in this or that situation may well be something we don't like. The Fear of God is the fear that God will do something we don't like. This Fear of God must, however, be set together with the goodness of God and our trust in him. God is good, and many have realized that God, in his goodness, was calling them to do what they did not want. The Fear of the God who is good appears throughout scripture, note the various times, as with Moses, where God says "I am calling you to lead my people," and the one he is speaking to replies "but I don't want to!" The one God calls ends up going. The realization that God may do that to me should cause me to be, in a way, terrified, or exhilarated (but there is still a sort of fear in exhilaration).
To trust in God, one must place all of oneself in God's hands. But then all of oneself is in his hands, and he gets to do as he likes with you, whether strike you with sores, send you as a missionary, or pastor, or plumber, or truck driver, or accountant, lock you away, sit you in doubt, or whatever else he may choose to do. We may not like it. We may love it. Either way, it is what God has chosen to do in us, and thus we ought to give glory to him for it, for he is good. Wherever God has you now, it is good for you to be there now. This is not to say that you should necessarily remain there, but that your being there now is good. Press on to the goal, but in the knowledge that it is Christ who works in you--your pressing on is also something God is doing with you.