I might try and rework this reasoning into a logical argument so we can better look at what is being asserted.
1. If God is omniscient, his foreknowledge of human choices is true.
2. If God foreknows all that will happen, then there is only one way that things will happen
3. If there is only one way that things will happen, then our choices are predetermined.
4. If our choices are predetermined then we lack free will.
5. God is omniscient
6. Therefore God's foreknowledge is true. (from 1 and 5)
7. Therefore, there is only one way that things will happen (From 1 and 2)
8. Therefore our choices are predetermined (from 2 and 3)
9. Therefore we lack free will (from 3 and 4)
I believe that premise (3) is false. God's foreknowledge that something
will happen doesn't necessitate pre-determinism because it does not imply that it
must have happened. In accordance with a
libertarian view of free will (which seems to be the definition this argument is working from), if one was to choose a different way, it's simply that God would have known differently than what he in fact does. Part of the problem I think when addressing this issue is that we confuse the logical order of God's foreknowledge. God does not know what we will do because he has decided what we will do - rather His foreknowledge is simply based upon what we will do. That is to say, God's foreknowledge doesn't determine our action, rather, our action is what determines Gods foreknowledge. Just because the chronological order of the knowledge is reversed, does not place a limit on our freedom (since the knowledge is still the logical consequent of our freedom).
Also note however the numerous ways that christian theologians have addressed this problem over the years. Under the argument provided above, one is assuming that a libertarian account of free will is true. I myself personally lean this way but it is worth noting other accounts of freewill such as
compatibilism which may be more associated with
Calvinistic doctrines. Such a view of freedom would provide an out at premise (4)
There are also theologians who deny that God's omniscience extends into the knowledge of the future. They maintain essentially that future counter-factuals are beyond knowable reality (and must be in order to be free) and so are even unknowable to God. Whilst I regard such an account to be bordering on heresy when it comes to Christian doctrine, if defensible it could provide an out at premise (1). This view is generally known as
open theism.
Given my response above, we needn't say that such individuals are destined for hell and heaven as though there is no other way it could have been. If libertarian freedom is true or at minimum even possible, then we cannot guarantee that these people were pre-dertemined/destined.
Nevertheless, it could still be asked that even if libertarian free were real why would God create people who would freely choose to go to Hell? Essentially I think that as long as it is even possible for God to have other overriding factors for allowing these choices, then such an objection cannot be taken too seriously. So what sort of over-riding factors could these be?
Imagine a possible world in which all were saved but the population only consisted of a few people. Any time God added anymore, there would always be at least one that freely chose to turn away. It could be that our current world presents the maximum possible amount of people "saved".
Now, of course, that may not be an overriding factor - but so long as it's even possible that there is an over riding factor then one cannot object that God acted unjustly or in a malevolent way to those who chose Hell.
For a good lay treatment of
theological fatalism check out
The Only Wise God.