God as a being outside of time can witness all of our free choices simultaneously, from the beginning to the end of time. It isn't foreknowledge or prediction, it's seeing the entire picture at once. "Future" is relative to us.
But suppose God is outside and above the Time-line. In that case, what we call "tomorrow" is visible to Him in just the same way as what we call "today." All the days are "Now" for Him. He does not remember you doing things yesterday; He simply sees you doing them, because, though you have lost yesterday. He has not. He does not "foresee" you doing things tomorrow; He simply sees you doing them: because, though tomorrow is not yet there for you, it is for Him. You never supposed that your actions at this moment were any less free because God knows what you are doing. Well, He knows your tomorrow's actions in just the same way-because He is already in tomorrow and can simply watch you. In a sense, He does not know your action till you have done it: but then the moment at which you have done it is already "Now" for Him.
http://lib.ru/LEWISCL/mere_engl.txt