Interesting.When we pray, it is not that the outcome is not already written and therefore predestine. But rather, we simple have not experienced it yet.
But things are simpler than that in reality. It is more like God asked us to decide on what and who we want to be for all of eternity, then snapped His fingers, and "in the twinkling of an eye" all the greater details of the consequences of our freewill decision came to be and were written in eternity with God. Then, as a means of judgement, He read the account of our freewill like a last will in testament, or like presenting evidence at a trial (after the fact)...which He does by revelations, wherein we hear and live out all of the outcome of our will in a first person experience, that which was written.
So, when we pray, we are simply updating our freewill with in that snap decision, that in reality occurred before the foundation of the world.
He also knew we would choose Him.
But it WAS our choice.
I hope we agree on that...
Seems like it.