I understand that there is a difference between saying that something has to be done and saying that it will be done but I'm not sure what that difference is in the real world.
I think when you get this, everything else will line up without too much problem. Look at what I said before about it:
I wrote:It is not a matter of reality. If I MUST do something and if I WILL do something, in both cases, I AM doing something REAL. Truth, in both sentences, is actual. The differences is in the nature of the reality.
The difference isn't in the event's actually happening. The difference is in the nature of WHY it happened. Let me give you a very simple example. Suppose a firefighter is called to put out an apartment fire. He walks in, sees the blaze, and puts it out. He then looks to discover the cause of the flame. Consider the following:
1) He finds a wall outlet had shorted out. It was old and finally gave away. The wall near it was dry, so the sparks started the fire; or
2) He finds the remains of a match near what is left of a strip of newspaper, and these under the charred remains of the window curtains. Closer analysis reveals small traces of kerosene at the tip of the curtains.
What is the difference in these two scenarios? In the first, the cause of the blaze was accidental. It happened because the tenant was (presumably) unaware of the faulty wiring and, being unaware of the problem, left it uncorrected until it resulted in the fire. But in the second scenario, the firefighter discovers that the tenet likely set the room on fire on purpose. The difference, then, in (1) and (2), is that (1) was accidental in nature whereas (2) was an act of will. In the former case, the insurance company will pay to have the apartment repaired. In the latter, the tenant goes to jail!
Notice what the difference is not. It is not that one happened in reality and the other didn't. Both happen. The question is the nature of the event. To use my original wording, the difference is in their ontology. In one case, the fire was accidental. That was the nature of the event in and of itself. In the other case, the fire was intentional in its very nature.
You should be able to see, then, that events have different kinds of natures (ontologies). Some events are freely chosen. Others are predetermined. Some are known by some agents. Others are unknown by some agents. That the event is or is not known does not change the nature of the event itself, be it a predetermine event or a freely chosen event. Thus, when I choose to do something of my own free will, that God necessarily knows what I will choose (as a necessary truth, God cannot NOT know what I will do), God knows what I WILL choose, not what I MUST choose. However, in the cases in which I MUST choose something (in which case, the word "choose" is probably not an appropriate word!), God likewise MUST know what I MUST choose, for both of these become necessary truths.
To put it still differently, God knows the NATURE of my choice, be that a circumstance-determined choice (by Him or something/one else or by whatever) or be that a self-determined choice (that is, a choice freely made by myself). The bottom line is that God knows what I freely have chosen. I made the choice, and God knew what the choice would be. Then note:
I am NOT free to make another choice, not because God knows my choice (indeed, had I made another choice then God would have known that), but rather because had I made the other choice, then I would not be free to choose the former. Since I am a temporal being (I experience time), I bind myself to my choices. My will binds me, not God's knowledge. Consider, for example, Frost's poem of the road less traveled. He chose to take one road, and in doing so, forever took from himself the opportunity to choose the other road. But had he chosen the other road, he would have forever lost the opportunity to choose that less traveled. That God knew which he would choose did not determine either Frost's choice or the nature of that choice (a free choice rather than a determined one). Rather, we may only say that God knew which he would choose, and what the nature of that choice would be (in this case, a freely chosen act).
Hope that helps clarify things.
edit: When you get a chance to address my response, would you also take a stab at a question of mine?
1. The existence of evil presupposes the existence of good (~good = evil);
2. People
ought to choose good over evil.
3. But any "ought" presupposes choice.
4. But if there is no choose, there can be no "ought," and if there is no "ought," there can be no distinction between good and evil, and if there is no distinction between good and evil, then evil does not eixt.
5. But evil does exist.
6. Thus, humans have free choice.
7. Machines do not have choice (they must do only as they are programmed, regardless of how much it appears they are making a choice);
8. In the absence of an immaterial part of man, humans are only machines (complex though they may be);
9. But if humans are only machines, then they do not have choice.
10. But that would violate (5), and thus, if (9) is true, then there is no such thing as evil.
So, then, my question: does not the presence of evil, our ability to choose things freely, and the compulsion to choose good over evil require the existence of the human soul? But if the human soul exists, is it not required that an immaterial aspect of the creation exists? But since the material cannot produce the immaterial, does not the existence of the immaterial in the universe require an immaterial cause for the universe (or, at the very least, for the immaterial aspect of the universe)? But would not such an immaterial cause also have to be personal, for how could a non-personal immaterial cause produce anything personal (indeed, the non-personal cannot produce the personal)? But what else is an immaterial, personal cause of the universe except God? And if this God is the source of good and evil, have we not discovered the existence of Theism's God?