God knows but YOU do not know until you do it. His knowing what you WILL do has nothing to do with the fact that you can CHOOSE to do either good or evil. Saying God knows what you will choose doesn't say WHICH you will choose, does it? And we don't know which we will choose until we choose, do we? So His knowing has nothing to do with OUR choosing. Got it?
It seems that with God knowing what I am going to do...then I have no choice in doing anything other than that. Whether I choose to do good or evil...has already been decided/known by God. I believe that if God knows something..then that is the way it will be. I may think I have chosen, but I can only do that which God knows is going to happen.