To continue the line of thinking, I will begin with a few words form our friend Gerhard Forde from his section on "the Work of Christ" in Volume 2 of Christian Dogmatics.
The statement from the Augsburg Confession points to the major question for this locus: Cur deus homo? Why did God become a human person in the particular way manifest in the actual story of Jesus? What is accomplished thereby? What does Jesus do? We are concerned about the action and the passion of Jesus and what results from them, as distinguished from his being. Why must he be crucified and raised? If it is a doing, a work of Christ, and not just a being with which we are concerned, then it must have some result, some effect. What is that effect, and why is there just this form of doing to achieve it?
Central throughout the discussion is the question of God's relation to the doing. Does God in Jesus do it for us, or does Jesus do it for God on our behalf? Is God propitiated, satisfied, or in some way altered by the event? Is God wrathful? Does God "need" Christ's work to become merciful? Or does God act on us through the event, changing us or the situation in which we find ourselves? Does God need the cross, or do we? Who is the real obstacle to reconciliation? God? Humans? Or some others -demons, perhaps?
I believe Forde is right. The why's and the what's are intertwined. Whether we are aware of it or not, any serious theory concerning the work of Christ on the cross must address, in particular, questions such as "Does God need the cross, or do we? Who is the real obstacle to reconciliation?" Right or wrong, these questions must be asked, thought about, viewed in light of Scripture, in light of the concrete facts, and answered.
Why so many differing views of the atonement? Are we just limited in our ability to comprehend and express higher truths such as this? Perhaps. But Forde offers one suggestion which I have to agree with.
Who has believed what we have heard?
And to whom has the arm of the Lord been revealed?
For he grew up before him like a young plant,
and like a root out of dry ground;
he had no form or comeliness that we should look at him
and no beauty that we should desire him.
He was despised and rejected by men;
a man of sorrows, and acquainted with grief;
and as one from whom men hide their faces
he was despised, and we esteemed him not (Isa. 53:1-3, as quoted in Christian Dogmatics by G. Forde)
"The question we face in considering the work of Christ is whether and to what extend our very attempts to find meaning for ourseles in the tragedy and horror of Golgotha are attempts to insulate against the offense." (Forde)
In other words, Scripture tells us plainly that we have a resistance toward the cross. It is a scandal for us, an offense, and we are both consciously and unconsciously biased toward looking for ways to insulate ourselves from its sting. If there is a way to water down or displace the offense, what it says about us in its full force, what it really means, we will find it.
Often, it becomes just a very necessary and important part of the whole salvation process, a number in the equation -an equation which we take down off the black-board and figure out and solve; a process we are a part of which just gets us to heaven. In other words, we familiarize it, like an inoculation, and thus lose the offensive character of it. We layer a theory over the actual thing. Theories are safe. You can chat about them over coffee or a beer. The cross is not safe.