If tweaking is what you are worried about, then rest easy. God doesn’t want to tweak you, or adjust you. God wants to completely transform you. According to C.S. Lewis, God says, “I have not come to torment your natural self, but to kill it. No half-measures are any good. I don't want to cut off a branch here and a branch there, I want to have the whole tree down.”
But He promises a good result. God, who cannot lie (Titus 1:2), promises a good result:
Romans 12:1-2: “Therefore, I urge you, brothers, in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God – this is your spiritual act of worship. Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is –his good, pleasing and perfect will.”
The question I face is this: Do I really want to be able to test and know God’s good, pleasing and perfect will? Do I want it enough to be changed? It may be that the “loss” I am so afraid of facing, will only occur if I remain where I am. Perhaps author Nancy Spiegelberg puts it best: "Lord, I crawled across the barrenness to You with an empty cup uncertain in asking any small drop of refreshment. If only I had known You better I'd have come running with a bucket."