Recently I read complete this article by Meredith Kline on Intrusion Ethics:
http://www.meredithkline.com/files/articles/The-Intrusion-and-the-Decalogue-MGKline.pdf
It is epic for understanding some of the more difficult to understand parts of the Old Testament. It is *very* hard going though. I can summarize it from memory:
People (who don't like the Bible to begin with) complain of the genocide commanded by God in the Old Testament and the Psalms that speak of dashing infants against walls and so on. Kline, using the overall context of Reformed Covenant - Federal - Theology explains such passages in a way that is lock down accurate (if you can discern on-the-mark/off-the-mark) and very different from any other explanation offered. First of all, though, I don't need an explanation. God kills. We don't need to explain it from our warped point-of-view. That is judging God from our level. But with that out of the way here is how Kline explains it:
He calls it Intrusion Ethics. The genocide of the Canaanites is an *intrusion* of the ethics of the *consummation (end times)* on the Canaanites. I.e. it is a type of the final judgment. And what is being *intruded* upon is *common grace.* Normally, this time between the Garden and the final judgement is regulated by common grace. Especially after the flood when God said He would no longer bring such deathly judgment on mankind that the flood brought. So common grace is given to not only God's elect but everybody else. So that the theatre of the world would be a theatre of salvation.
But Kline deftly explains that in the consummation ethics are different. We are actually to hate our enemy then, to use an example. In this era of common grace we are to love our enemy. But once God unleashes the final judgment on the rebels we would be betraying God to love His enemies.
So this explains the imprecatory psalms as well. Those psalms that invoke judgement and violence and curses on one's enemies. They represent an intrusion of the consummation (final judgement) ethics. (And Kline points out that we are not to think we can do an intrusion on anybody, only God manifests that, and since the Bible is set now God is only talking through it, so if anybody says God told them this or that it is lunatic.)
He also points out that there are also instances of intrusion in the Old Testament involving salvation rather than just judgment. For instance when Hosea is ordered by God to marry a prostitute. That goes against the laws of National Israel, but they are an example of the intrusion of the ethics of the consummation where Christ takes as His bride sinful believers. Once adulterous. We become His bride.
The order to Abraham to sacrifice his child Isaac is the same. It is an example of an intrusion of consummation ethics. In this case God's sacrifice of his own Son, the Second Person of the Trinity, Jesus Christ.
So Intrusion ethics means the intrusion from above (like from out of time down into the world) of the 'ethics of the consummation' into the world of common grace and overriding that common grace. It is involved with typology. (This element, typology, is a bigger subject in the Kline article than I'm giving it here.)
Kline is careful to explain how common grace ethics differs from ethics in the consummation end time.
It's a difficult read, but it is epic in establishing understanding of the unity of the Bible, typology, explaining difficult (difficult for some) passages, and even beyond all that the subject has epic edges to it that give a vision of the Bible that is raw and new and on-the-mark.
You have to know Covenant - Federal - Theology to understand Kline, but just so you know the mountain is there you will climb it. - C.
ps- I also had a question on a totally different subject: what is the 'first resurrection' mentioned in Revelation 20:4-6? I thought to myself, "I should know that." So I looked into it. Dispensationalists have their own take, so I wanted to know the Covenant Theology take, and it is this: I'll just give it short hand without going into context and everything: the first resurrection is regeneration by the word and the Spirit. I.e. if you have that then you are blessed and won't suffer the second death. What is the second death? It is the lake of fire. Judgment to hellfire. Why is it called the second death? Because the first death is the death of our physical bodies. Final question: if the first resurrection is called the first then what is the second resurrection? The second resurrection is the resurrection of our bodies at the Second Coming. The first resurrection takes us to be with Christ in Heaven when we die (and regeneration is the beginning of that, it itself is eschatololgical in that we are born again and with Christ above even now, but in full when we die). The second resurrection gives us a glorified body, our old body but very much changed.
pps- Meredith Kline has two articles on the first resurrection at that site linked above. His take is a bit different, but in line with what I've written above. He prefers to call the first resurrection solely our physical death when we then are literally resurrected up to God in paradise (Heaven). But regeneration is the cause of that and the beginning of it, so it is OK (and I and most Reformed theologians think more accurate) to call the first resurrection regeneration by the word and the Spirit.