I've got a lot of interesting responses, both by blog and email, to my question about dying for sins. Because of their number, I'm going to try to address them thematically rather than individually, though I will refer to some individual people. So, here goes:
Mystery
Several writers have pointed out that Jesus' sacrifice is essentially a mystery, and we cannot comprehend all the details. Disputations alluded to this, leading me to a wail of despair: what's the point of talking about it then? I think I overreacted, and fortunately some Christians, including Peter Nixon and Eve Tushnet in emails, assured me that just because something's a mystery doesn't mean it isn't worth looking at. Eve wrote:
For my own part, I tentatively advance the theory that a mystery (in the Christian sense) is something where you can know _why_ it happens, but not _how_: the Trinity, the Incarnation, the Crucifixion, the Church as Body of Christ all come to mind. I think some of your questions are how-questions, which you're unlikely to get answered, but some are why-questions, which I'll try to address next week, and which, like I said, I think Anselm handles really well.
Minute Particulars expressed a similar idea: "And, as others have warned, slapping the 'mystery' label on doesn't mean 'give up!, we'll never know!' Rather it means quite the opposite: 'stay and stare, look again, contemplate over and over.'"
So I will stop asking everyone to "know the mind of God." But there are still some points to what I asked that I don't think require that.
In loco parentis
In response to my post questioning subtitutional atonement, Josiah Neeley sent an interesting email:
Here's an example told to me when I was a kid: suppose that a rebeleous kid is pulled over for speeding. When the cop gives him a ticket he laughs, saying that his father is a judge and loves him so much that he would never see him come to any harm. The kid goes to court where, as expected, the case comes before his father. His father, however, finds the son guilty and imposes the maximum fine. The kid is stunned. He has no money, and if he can't pay must spend the next 90 days in jail. The father, having passed sentence, steps down from his bench, takes off his judge's robe, gets out his checkbook, and pays the fine.
Good things about this analogy: It shows, first off, that it is possible to (quite literally) pay for another person's crimes. It also highlights a way in which taking on another person's punishments is different from not punishing them. We might reasonably suppose that the father's gesture of self-sacrifice would cause the son to mend his ways and go and sin no more. This would be particularly plausible to suppose if the judge was not rich and paying the fine required him to take on extra work, to do without, etc. in order to pay off the debt.
By contrast, if the father had just let the kid off, it's unlikely he would have mended his ways. If anything, he would be more likely to commit crimes, since he would conclude that he wouldn't be punished for them. The situation would also be lawless.
I think I see what he means here. This is not just about forgiveness, but imparting a moral lesson for the future. It makes forgiveness an exception to the rule.
The trouble I see, though, is that it only works for one act of forgiveness for one specific sin. If I understand it right, Jesus theoretically died for all our sins, down to the present day. After all, I am told that Jesus died for my sins, and I was born an awfully long time after the Crucifixion. But I think this is getting ahead to the last part of the post, so more anon.
Love hurts
Although Josiah was defending substitutional atonement, Peter Nixon, who originally described the theory, seem to be backing off it. He reprinted a reader's letter objecting to the idea that "God accepts as legitimate the death of an innocent," which was one objection I raised myself. The reader went on:
You are right in saying that it is difficult to explain. I like to think of it as follows: God is so merciful, that he himself became a mortal, and was put to death on account of our sins. What greater indication of the sinfulness of humanity than the brutal judicial murder of an innocent man? But through his resurrection, Jesus conquered sin and death and pointed out the way for us to follow. By accepting his infinite mercy and following him, by uniting ourselves with Christ, we are "saved". In the great words of St. Peter, God became man so that man could share in the divine nature. This is the wonderful truth of our faith, and it is so much richer and more beautiful than the vengeful deity theory of vicarious atonement, which is accepted by protestant fundamentalists today.
I'm kind of unclear on how the Incarnation and Crucifixion demonstrated God's mercy. Did he want to show he was capable of forgiving people for trying to kill him? This also raises again something I asked earlier: how Jesus' death, as opposed to his life, "pointed out the way for us to follow."
Later Peter quoted the Pope saying something similar:
God is always on the side of the suffering. His omnipotence is manifested precisely in the fact that He freely accepted suffering. He could have chosen not to do so. He could have chosen to demonstrate His omnipotence even at the moment of the Crucifixion. In fact, it was proposed to Him: "Let the Messiah, the King of Israel, come down from the cross so that we might see and believe." (Mk 15:32) But He did not accept that challenge. The fact that he stayed on the Cross until the end, the fact that on the Cross He could say, as do all who suffer: "My God, my God, why have you forsaken me?" (Mk 15:34), has remained the strongest argument. If the agony on the Cross had not happened, the truth that God is Love would have been unfounded.
I must admit, probably one reason I am not presently a Christian is that the whole idea of a suffering God doesn't really impress me. The general subtext I get from a lot of Christians talking about the Crucifixion is that love = pain; the way you really prove your love for someone is to suffer horribly. I don't like that as a conception of love. Certainly love sometimes calls upon you to suffer for another person, but unless that suffering is unavoidable, it's just gratuitous. I don't think you love someone less if you aren't called upon to suffer for them. That's why I asked the question that Disputations so disliked, whether the grisly business was necessary.
Though I may well be misreading, the implication I get from the above passages is that God descended and suffered so he could feel what we feel, which shows his great love. But I do not see a great point in simply suffering because someone else is suffering. If I cut my finger, I don't expect my mother to cut her finger to show that she loves me. I expect her to get me a bandage.
What really happened
But of course, most Christians would say God wasn't simply suffering along. Jesus' death achieved some sort of atonement, a reconciliation between God and humans. This brings me back to a question I raised in this post, which no one seems to have addressed yet: what did the atonement actually change? I think this seems so obvious to most Christians that it hardly bears explaining, but I don't understand it. In this post from Kairos, he describes "a moment ... when some other will bear our sins away from us, and free us from their terrible burden." This is supposedly what the Crucifixion was, and yet I have yet to meet a Christian who actually seems freed from his sins. For instance, in a more recent post, Kairos says: "I find that almost every urge and impulse to do or not do something is wrong... If I find myself really wanting to do something, wanting in a state of near lust or gluttony, it usually turns out to have been the very worst thing I could have done at that moment."
Not to pick on the KairosGuy: every Christian I know freely admits to sinning. They are, after all, still born into the fallen world. Many of them also fear ending up in hell, at least sometimes. So what exactly are they free from? How are they different from anyone in the Old Testament, those who likewise struggled to be good and often screwed up? How are they treated differently by God, who seems to sometimes punish and sometimes forgive, just like he did in the OT?
I apologize again if these questions seem boneheaded, but as I've read the responses I've been feeling more strongly we need to establish what The Great Atonement actually was before we can talk about how or why it happened. But thanks to all who responded, for being so thoughtful and courteous with this annoying heathen.