Middle knowledge

Middle knowledge is one of the nuttiest concepts that Christian theologians have yet to cook up, concerning predestination's compatibility with free will. It supposes that God had already decided before you were born whether you are going to heaven or hell, yet whether you go to heaven or hell is simultaneously and entirely based on your own freely-willed decision to accept the Gospel message.

The theory
The theory claims that God knows what you would 'freely' choose to do in every possible circumstance, even in circumstances which never actually occur. This knowledge is known as 'middle knowledge'. Thus, he can arrange things so that you go to heaven or hell forever, as he chooses – if he wants you to go to hell, he'll make sure you undergo whatever circumstances would result in you freely choosing hell; if he wants you to go to heaven, he'll make sure you undergo whatever circumstances would result in you freely choosing heaven. So you have free will, within a certain extent. Sorta.

Does this make sense?
What does any of this mean? Does anyone know? Do even the proponents of this idea really understand it? Probably not. But William Lane Craig thinks it is one of the deepest ideas anyone has ever thought of. Perhaps it's just a bit of sophistry employed so that certain denominations can have their cake and eat it too regarding free will vs. omnipotence.

Warning
You'd better believe it or you're headed straight for the really not nice place.