I've been reading through Andrew Hill's NIVAC commentary on Chronicles with Sam, and I was intrigued by one of his so-called Contemporary Application sections (which in Hill's commentary sometimes stretch the boundaries of what I think the NIVAC series intends for those sections, often verging into abstract, theoretical constructs that have not much more than tangential connection with the text and not a very clear practical value). In his application of I Chronicles 18-20, a section about David's military victories, Hill spends four pages explicating the classic Christus Victor view of the atonement (literally "Christ the Conqueror"). In the process, he cites Greg Boyd's God at War: The Bible and Spiritual Conflict, which argues that the battle between God and Satan does a lot more work philosophically and theologically than most evangelicals want to allow for. I happen to think Boyd goes way too far with this by accepting that God can't predict what Satan will do and by coming a little close to a dualism that treats God and Satan as near-equals. He insists that God will win in the end but doesn't give much philosophical or theological ground for how even God knows that Satan won't win in the end, never mind for us to be assured of it. Since this is largely a response to the problem of evil, I don't think it ultimately succeeds. The most crucial element of the Christian response to the problem of evil is that God's plan contains all the details of what will happen, and even the smallest details of what will happen are included in God's perfect, sovereign plan. So I've never thought that Boyd's overall view is even good at doing the one thing that he wants most of all to achieve with it.
But on the Christus Victor issue, I think Boyd has a point (although I hope to show that his point needs to be dulled, as my brother used to say). For the record, my general view of the atonement is that most of the theories of the atonement reflect part of what the atonement accomplishes. Jesus' death surely does serve as an example for us to sacrifice ourselves in love, but that doesn't come close to expressing its main purpose. Jesus' death also provides a redemption, i.e. a buying back of those who belong to sin and death to bring them into life and into service of God rather than slavery to sin. It takes care of a legal death penalty that all fallen human beings deserve for committing the highest of all crimes, rejection of the perfect and loving creator. It removes the corruption that cannot enter God's presence and makes us holy and thus allows reconciliation with God. [A great place to investigate this subject in detail is to read Rebecca Stark's blog series The Purposes of Christ's Death.]
And yes, Boyd is right that it constitutes a conquering of all evil raised up against God, signaling victory over all God's enemies. It is thus the fulfillment of all the divine warrior imagery throughout the Hebrew scriptures, including the kind of thing said about God fighting for his people Israel, which the psalms and prophets did attribute to David's military victories. Thus it's not that much of a stretch for Hill to bring this in with a discussion of I Chronicles 18-20. But I think Boyd takes this too far, as most who emphasize just one element of the atonement do. While he doesn't make the mistake of reducing the atonement to Christus Victor, he does take it to be the fundamental purpose of the atonement, on which all the other elements are based. On that point, I can't agree.