Hey Karen, how's your head? Better, I hope!
No, I don't believe in the 'power' of prayer, I believe in the power of God. I believe that prayer is a way of getting us in tune with God and His will..."not my will but thine be done." I believe in God's absolute sovereignty over every situation and circumstance in life, the good, the bad and the ugly. I think that's the lesson Job learned. Can you imagine being at the scene of the Crucifiction, for instance, and even remotely believing that it was God's will and something 'good'? But yet it was. And since we don't know the end from the beginning, and what His will may be in any given circumstance, or what may really be the best answer in any given situation, we are really at a disadvantage and don't really know how to pray, but He invites us to pour our hearts out to Him, to present our requests to Him, with the promise that the God of peace will be with us. He doesn't promise a 'yes' or a 'no', but peace no matter what the answer is because we know that whatever the answer is, it is His will.
I think folks believe they have free will, but do we really? We certainly 'sense' that we have free will, but how 'free' is it? Advertising agencies know how malleable we are, easily swayed and influenced. We are like putty in their hands. I believe God 'influences' us in a similar way, He is the potter, we are the clay. There's a verse somewhere in the Bible that says something like, a man plans his way, but the Lord orders his steps. The Bible does talk about the will of man, but it never states anywhere that it is 'free', other than a reference to a 'free-will offering', which means giving without obligation or under duress of any kind.
Yes, I believe everything is predestined and will be accomplished as it has been planned, and we have the privilege of participating in those plans as He leads and 'influences' us in the accomplishment of His will.