Obviously when doing ethics one’s view of the relationship between the Mosaic law and the New Testament believer. Which ever view you take it will impact upon your ultimate ethic for the Christian today. Now as one who’s not to keen on the whole tripartite division of the law of moral/civil/ceremonial (mainly because I think its an imposed framework that Calvin borrowed from Aquinas and not from reading his Old Testament), I found Michael Hill’s brief comments extremely helpful. Speaking about the stage of redemptive history containing Israel and their law he says the following:

“The significance of this stage in salvation history for ethics is often over emphasized. The Law of Moses does not provide a complete and binding guide to Christian morality. On the other hand it should not be dismissed as irrelevant. The basic shape of God’s rule, and God’s just order established at creation, is confirmed and further delineated in the Law. Yet it is delineated in positive and negative ways. For example the people of Israel are told not to commit adultery, a negative command.

Nevertheless the Law gives us, as Christians, a glimpse of God’s just order. Aspects of the configuration of his good order are revealed. There is good reason for the negative aspects being included. The revelation comes to people who have rebellious hearts. Even though God has called them and dealt graciously with them they are still, as Paul puts it, slaves to sin. The negative aspects address this rebelliousness. The negative pattern is exposed in the Ten Commandments. Only three of the commandments are stated in positive terms. The rest are asserted negatively. The sevenfold repetition of ‘do not’ presupposes a spirit of rebellion and disobedience.

While Christians are not under the package called the Law, the moral elements in the Law are part of a continuum that gives shape to an ideal. This continuum reaches from creation to Christ. Many people like to divide the regulations and laws that give shape to God’s covenant with Israel into moral, cultic and civil elements. In this way it is hoped that the cultic and civil elements can be jettisoned with the coming of the New Covenant in Christ, and the moral component retained. However the Bible itself does not operate in this way. The Old Covenant is seen as a discrete unified package with a number of aspects, not parts. These various aspects cannot be unravelled and treated as parts. Moreover the Old Covenant and its Law is seen as a shadow of the reality to come in Christ. The partial gives way to the complete. This is true of the cultic and civil aspects as well as the moral.” (The How and Why of Love, p.74)