If all are included, why final judgment and hell?

A question I'm frequently asked concerning trinitarian theology goes something like this:
If all humanity is reconciled to God through Jesus, then why is there a final judgment and hell?
To answer this question, we must begin with the biblical answer to the question that takes us to the foundation of all truth, namely, Who is Jesus?  

Scripture declares Jesus to be fully God and fully human. As the unique God-man he is both the Judge and the one in whom all are judged; the Savior and the one in whom all are saved. Through his vicarious (representative and substitutionary) humanity, Jesus stood in, and still stands in for us all. When Jesus, who bore all our sin, was judged, we were all judged. When he died to pay for all our sin, we all died. When he rose victorious from death, we all rose. And when he ascended to the Father's side, we all ascended with him and in him (2Cor. 5:14, Eph. 2:4-10).

In his dual role as both our Savior and our Judge, Jesus does not come to us with a “split personality” - he is not one kind of God-man as Savior, and then another kind of God-man as Judge.  Said another way, there will not be a different Jesus who shows up at the final judgment from the one we have already seen at the cross.  Or as Michael Card wrote in one of his songs: "When we look into our judge's eyes, we see our Savior there."  Amen Michael! 

As we think about the twin issues of hell and judgement out of the framework of what we know to be true otherwise of the triune God in union with all humanity in the person of the God-man Jesus, the following points begin to emerge: 

• Every person who ends up in hell will have been included already in Jesus and thus reconciled to God—forgiven; adopted; accepted. It is only their subjective unbelief – their personal alienation and thus rejection of God’s forgiveness (God’s acceptance of them) that leads them to persist in their “no” to God’s resounding, freely given “Yes” to them (and to all humanity).  

• The final judgment involves the general resurrection, when all will see Jesus and themselves in Jesus, clearly; and this creates for alienated, non-believers a crisis that may constitute for some their first invitation to repentance and belief.

• And so, in the final judgment, the issue at hand, and thus the “bottom line” question for all (believers and non-believers alike), will be this:
Do you accept God’s love, God’s forgiveness, and God’s acceptance that is yours in Christ? Will you come into the wedding supper?
To refuse to believe, accept and embrace, is to choose alienation from the source of a person’s very being and from fellow humans – and this alienation (which, by their personal choice continues) is a miserable “hell” – likened in Scripture to “outer darkness” and “ever-burning fire.”  

In "The Problem of Pain," C.S. Lewis wrote this about hell:
I would pay any price to be able to say truthfully 'All will be saved.'  But my reason retorts, 'Without their will, or with it?' If I say 'Without their will,' I at once perceive a contradiction; how can the supreme voluntary act of self-surrender be involuntary? If I say 'With their will,' my reason replies 'How if they will not give in?'
We’re dealing here with the mystery of evil in a universe where God is fully sovereign, and the reality that God will never strip any person of the free will that he has given to them.  They must remain free to say “no” as well as “yes” to God’s “Yes” to them - a "Yes" given freely in and through Jesus in union with all humanity (2Cor 1:18-20). 

Consider what Robert F. Capon says in his book "The Mystery of Christ..and Why We Don’t Get It” (p. 10): 
There is no sin you can commit that God in Jesus Christ hasn't forgiven already. The old baloney about heaven being for good guys and hell for bad guys is dead wrong. Heaven is populated entirely by forgiven sinners, not spiritual and moral aces. And hell is populated entirely by forgiven sinners. The only difference between the two groups is that those in heaven accept the forgiveness and those in hell reject it. Which is why heaven is a party—the endless wedding reception of the Lamb and his bride—and hell is nothing but the dreariest bar in town.
Back to C.S. Lewis, this time from his book "The Great Divorce":
There are only two kinds of people in the end; those who say to God, ‘Thy will be done,’ and those to whom God says, in the end, 'Thy will be done.'  All that are in hell, choose it.  Without that self-choice there could be no hell.  No soul that seriously and constantly desires joy will ever miss it. Those who seek find. To those who knock it is opened.
Trinitarian theologians are often accused of denying the reality of hell. Karl Barth was often accused along those lines. A friend of his shared a rebuttal he once gave to this accusation - it involved a vivid dream in which Barth saw hell as an…
…immense desert..[that was] unbearably cold, not hot. In this cold, forsaken desert, there was sitting one person, very isolated, and very lonely; so much so that Barth became depressed just observing the loneliness. Ending the narration of his dream, Barth said to his friend, 'There are people who say I have forgotten this region [hell]. I have not forgotten. I know more about it than others do. But because I know of this, therefore I must speak about Christ. I cannot speak enough about the Gospel of Christ' [from "Memories of Karl Barth," by Eberhard Busch, in "How Karl Barth Changed My Mind," ed. by Donald McKim, pp.13-14].   
Scripture speaks of final judgment and of hell precisely because God gives us freedom to respond (in faith or in disbelief) to what he has done for us in Christ. We are included in Christ, but we can refuse that inclusion. We are reconciled to the Father through Christ, but we can refuse that reconciliation, remaining forever in alienation toward God within our own (distorted, alienated) minds. Such refusal has horrific and eternal consequences, but it does not negate the universality of what God has done for all humanity in and through Jesus Christ.