How to Use the Law
Teaching in higher education for ten years taught me that you cannot assume people will do what’s obviously right, and they will not admit to understanding what is obviously wrong. When people are left without marked boundaries to exercise their own free will, they will defy their own conscience, ignore any sense of right and wrong, hurt themselves, and hurt other people. A written code must exist to define right and wrong behaviors and define the consequences for those behaviors. The Mosaic Law was given for this very reason, to define sin and the consequences of sin. Romans 3:19-20:
Now we know that whatever the law says, it says to those who are under the law, that every mouth may be stopped, and all the world may become guilty before God. Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin.
The Mosaic Law is useful to us, even as Christians, if we use it in the right way. This was Paul’s message in 1 Timothy 1:8: “But we know that the law is good if one uses it lawfully…”
Indeed, the Old Law should be used by Christians. The apostle Paul said in Romans 10:14, “For whatever things were written before were written for our learning, that we through the patience and comfort of the Scriptures might have hope.” Things written before (the Old Testament) should be studied. It should be understood. We should learn from it. If you’re reading the New Testament, you’re actually reading the Old Testament, too. Almost every book of the New Testament includes quotes and illusions to the Old Testament. When you quote the New Law, you’re often quoted the Old Law, too. This point is simple and self-evident, but the difficulty is in the details. How exactly should the Old Testament be used for Christian people living under the New Testament? In what specific ways should we apply principles and practices from the Mosaic Law to the Christian Law?
The Mosaic Law – and the entire Old Testament – should be used to understand the outcome of sin. We see an example of Paul doing this very thing in 1 Corinthians 10:6, 11:
Now these things became our examples, to the intent that we should not lust after evil things as they also lusted…Now all these things happened to them as examples, and they were written for our admonition, upon whom the ends of the ages have come.
Christians are admonished by the example of these disobedient Jews.
The Mosaic Law should also be used to increase our understanding of the New Testament. For example, the book of Hebrews makes the point that Jesus Christ is a better priest and better mediator, having confirmed a better covenant established on better promises. We understand the superiority of the New Covenant only when we understand the Old Covenant. The Mosaic Law also informs how we understand Christian doctrines, such as baptism. Christian baptism is compared to events in the Old Testament, like the flood (1 Peter 3:20-21), the crossing of the Red Sea (1 Corinthians 10:2), and even circumcision (Colossians 2:11-12). The Mosaic Law is also used as a pattern for how we handle church finances (1 Corinthians 9:8-10).
While the Old Law and New Law were established by the same God and have many of the same basic requirements, they are not the same covenant. The New Covenant replaces the Old Covenant. It is not just an appendix to the Old Covenant. It is not just a revised and expanded version of the Old Covenant. We serve God according to the indwelling of the Spirit, not by letter of the law. The Old Testament was fulfilled and finished through Christ. This point is made several times throughout the New Testament, including Romans 7:6, “But now we have been delivered from the law, having died to what we were held by, so that we should serve in the newness of the Spirit and not in the oldness of the letter.”
For this reason, we must be aware of some very specific traps and pitfalls. The Old Testament is not a means of justification or righteousness. In other words, observing the Old Law is not inherently righteous or inherently good. Observing the Old Law is not a path to justification. This is Paul’s essential point in Galatians 2:16:
…knowing that a man is not justified by the works of the law but by faith in Jesus Christ, even we have believed in Christ Jesus, that we might be justified by faith in Christ and not by the works of the law; for by the works of the law no flesh shall be justified.
Observing the ceremonial requirements of the law does not make us righteous in the eyes of God. Participation in circumcision, sacrifices, and sabbaths does not take away our sins. There are no special privileges or blessings that come with observing Jewish customs from the Law.
A Christian should use the Old Testament but don’t overuse it. Use the Old Testament to understand and verify New Testament doctrines, but not as the basis of New Testament doctrines. Use the Old Testament to see examples of faithfulness, but not as a means of justification.