[The following is based on: Hays, J. Daniel (2001) Applying the Old Testament Law Today.  Bibliotheca Sacra 158: 629: 21-35.  The article is available here.]

Christians uphold some of the OT laws (such as the Ten Commandments), but violate others (including those relating to food, hygiene, and clothing).  We tend to judge their validity on their apparent relevance, but this is abitrary.

How then might we proceed?

The traditional appoach

The traditional approach is to distinguish between moral, civil and ceremonial laws.  On this view, the civil and ceremonial laws applied only to ancient Israel; the moral law is timeless.

This approach is flawed in a number of ways:-

(i) the distinctions have no basis in Scripture itself.  There is no indication in the text, for example, that Leviticus 19:18 is binding but Leviticus 19:19 is not.

(ii) it is often difficult to decide which category a particular command falls.  All the commands are theologically-based, Leviticus 19 beginning with a statement of God’s holiness.  How can a law that is related to God’s holiness not be moral?

(iii) even in the Ten Commandments, the clearest examples of moral laws, problems arise.  Is the 4th commandment moral or ceremonial?  And if we regard it as a moral law, do not the vast majority of Christians break it anyway?

A narrative approach

A narrative approach says that the laws are embedded in Israel’s history, and are not to be regarded as timeless universal codes.

The giving of the Ten Commandments is placed very firmly within this unfolding history.  The narrative is as part of the canon as the law. When the Pharisees accused the disciples of breaking the Sabbath law, Mark 2:23-28, Jesus appealed to a narrative passage, 1 Samuel 21:1-9, to justify their behaviour.

The narrative approach overlooks the law’s theological content.

God introduced the law in a covenant context.  This was associated with God’s promise to dwell with his people, and this in turn was associated with instructions regarding the ark and the tabernacle.

(i) The Mosaic covenant was closely associated with the conquest and occupation of the Promised Land.

(ii) The blessing of the covenant were conditional.

(iii) The Mosaic covenant is no longer a functioning covenant, Hebrews 8:13; Galatians 2:15f; Romans 7:4.  Paul does not base his moral teaching on the law, but on the gospel.

How then should we understand Matthew 5:17?  We should note that Jesus is not referring here specifically to the law, but to the entire Old Testament.  Jesus says that he has come not to ‘abolish’ but to ‘fulfil’ the law and the prophets – to bring to their intended meaning.  He fulfilled the Scriptures in their entirety, and (later in the Sermon on the Mount) he declared himself to be the final authority over the law, restating some of the laws and modifying others.  The law must be interpreted and applied in the light of Jesus’ coming and in the light of the profound changes introduced by the New Covenant.

In conclusion, the Old Testament law is tied to the Mosaic covenant and integrally connected to Israel’s life in the Promised Land.  Christians are not related to the land, and the Mosaic covenant is obsolete.  Therefore, the Mosaic law is not valid as law over believers today.

A suggested approach

A suitable approach ‘should be an approach that (a) is consistent, treating all Old Testament Scripture as God’s Word, (b) does not depend on arbitrary nontextual categories, (c) reflects the literary and historical context of the Law, placing it firmly into the narrative story of the Pentateuch, (d) reflects the theological context of the Law, and (e) corresponds to New Testament teaching.’

An approach that satisfies these criteria is principlism.

Identify what a particular law meant to the original audience.

What was the historical and literary context?  How did it relate to the covenant?  How did it relate to Israel’s life in the land?  What particular situation does the law address?

Determine the differences between the original audience and believers today.

We are not under the old covenant, but the new.  We do not dwell in the Promised Land.  We do not approach God via the sacrifice of animals.  We live under secular governments and not a theocracy.  We face pressures not from Canaanite religions but from non-Christian worldviews and philosophies.

Develop universal principles from the text.

What timeless truths lie behind the text?  ‘These universal principles will often be related directly to the character of God and His holiness, the nature of sin, the issue of obedience, or concern for other people.’

Correlate the principle with New Testament teaching.

Is the OT law restated, modified, or annulled?  Note that some OT laws are extended (rather than restricted) in order to include attitudes as well as actions.

Apply the modified universal principles to life today.

In 1 Corinthians 9:9 Paul cites Deuteronomy 25:4 in a principlist way.  We would probably not regard the Deut law as ‘moral’, but Paul regarded it as applicable (not as a law, but as a principle).

Conclusion

‘The traditional approach of dividing the Mosaic Law into civil, ceremonial, and moral laws violates proper hermeneutical method, for it is inconsistent and arbitrary, and the Old Testament gives no hint of such distinctions. This approach errs in two ways. On the one hand it dismisses the civil and ceremonial laws as inapplicable. On the other hand it applies the so-called moral laws as direct law. In addition the traditional approach tends to ignore the narrative context and the covenant context of the Old Testament legal material.

‘Principlism, an alternative approach, seeks to find universal principles in the Old Testament legal material and to apply these principles to believers today. This approach is more consistent than the traditional one, and it is more reflective of sound hermeneutical method. It also allows believers to see that all Scripture is “useful for teaching, rebuking, correcting and training in righteousness” (2 Tim. 3:16).’