You wrote:
Point well taken! Christianity is based on the belief of certain facts, and fulfilled prophecy is among the most important of facts. God is not just a "good guesser".And yet I haven’t mentioned the first reason that comes to my mind. It is that, for the skeptic, Open Theists have all but eliminated that chief internal biblical evidence the Bible uses to prove God—fulfilled prophecy. This is especially important for predictions involving people in which God is not manipulating man’s sinful responses. For to predict the actions of sinners who engage in sin—an activity God always opposes without exception (I take great issue with the common translation of Rom. 8:28, which implies God uses sin for His own ends, i.e., the good of the believer)—is to show that God is able to know the future without in any way manipulating future sin to come to pass.
I suppose the open theist would argue that God fulfills prophecy by intervening as necessary in order to bring the fulfillment about. But then in that case, He must void free will, and it would seem necessary at times for Him to override free will in a large number of people to bring about His will. I am not arguing that God can not or does not do this, only that at least some of the time the open theist must admit (at least it seems to me) that God overrides free will. The question then becomes how often? To maintain their position, I would think that they would argue that the amount of time God intervenes is miniscule, but God can intervene by many means to bring about His will, and what proof have they that He does not directly intervene routinely? The answer can not be found in logic.
I ordered that tuna sandwich, all the while believing that God knew I would do so, and the only compulsion I felt was my preference for a tuna sandwich. Perhaps God made me compulsively desire tuna sandwiches, but then the time before I ordered chicken. And then again, perhaps God was totally surprised by all this. Hmmm..