Christians struggle with the idea of "free will". This is not unreasonable as there is no such thing, only an illusion of "free will". They want it to exist, despite the fact that this means that there can be no "God's Great Plan" to draw the earth to Armageddon.
The Calvinist apologist is good but he, like any good apologist, simply ignores the verses of the NT that state that there is no free will.
Romans:9:14 What then shall we say? Is God unjust? Not at all! 15 For he says to Moses,
“I will have mercy on whom I have mercy,
and I will have compassion on whom I have compassion.”[f]
16 It does not, therefore, depend on human desire or effort, but on God’s mercy. Here we see that, regardless of what you have done, it's God's decision where you end up.
17 For Scripture says to Pharaoh: “I raised you up for this very purpose, that I might display my power in you and that my name might be proclaimed in all the earth.”[g] 18 Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden. This is the example posted earlier. God made Pharaoh bad so He could show how good He was by saving the Israelites. Yet where do we think Pharoah is? Heaven or Hell?
19 One of you will say to me: “Then why does God still blame us? For who is able to resist his will?” This is a very good question.
20 But who are you, a human being, to talk back to God? “Shall what is formed say to the one who formed it, ‘Why did you make me like this?’”[h] And basically the answer is "Piss off, who do you think you are even asking that question."
21 Does not the potter have the right to make out of the same lump of clay some pottery for special purposes and some for common use?
22 What if God, although choosing to show his wrath and make his power known, bore with great patience the objects of his wrath—prepared for destruction? This is quite amazing, Paul says "God puts some people on earth to live, die and stoke the fires of hell. Hello people! It's part of His Plan! Duh!" I bet the crowd weren't at all fooled by that one.
23 What if he did this to make the riches of his glory known to the objects of his mercy, whom he prepared in advance for glory— Don't forget, Paul is talking to the Romans, who think that only Jews can go to heaven (Indeed, that is what Jesus said.) So now his weasel words are saying, "Ah! Yes, but now we know that God makes assholes and good people and the assholes go to hell, and that he does this stuff just to show how powerful He is to the Jews! And then he adds...
24 even us, whom he also called, not only from the Jews but also from the Gentiles? 25 As he says in Hosea:
“I will call them ‘my people’ who are not my people;
and I will call her ‘my loved one’ who is not my loved one,” Yes, that's right, Romans can go to heaven (Let me tell you about my "EZ tithing Plan") God says so!
And if you look at Hosea:1:9 you will see that Paul has quoted out of context (at least with modern Bibles.)
So, Christians know there is no free will really but they lie about it and pretend there is.