We are quick to explain, and for good reason, that the Old Law was nailed to the cross (Col. 2:14). Unfortunately, the reason for abandoning the first covenant is often misunderstood. While it is true that the Old Law was abolished when Christ sealed the New Covenant in His blood, the Old Covenant was not pushed aside because it contradicted the New Testament, but because it was fulfilled by it. Jesus makes this point clear in the beginning of the mountain message: “Do not think that I came to destroy the Law or the Prophets, I did not come to destroy but to fulfill” (Matt. 5:17). Christ follows this statement with 30 verses (Matt. 5:19-48), explaining the proper application of Old Testament Law. In the process He effectively binds the keeping of the principles in these laws by His disciples—including Christians today. Therefore, many of the commandments in the New Testament find their root in Old Testament Law.

The fact that the commands of the Old Testament and New Testament remain similar is not surprising. Both Covenants “hang” on the two greatest commandments. Jesus explains these commands in Matt. 22:37-40: “‘You shall love the LORD your God with all your heart, with all your soul, and with all your mind.’ This is the first and great commandment. ‘And the second is like it: ‘You shall love your neighbor as yourself.’ On these two commandments hang all the Law and the Prophets.” Jesus quotes these commandments from Leviticus 19:18 and Deuteronomy 6:5 (cf. Deut. 10:12, Deut. 30:6). James, John, and Paul all make direct references to these Old Testament laws. The reason for this is simple: God’s laws are based on principles, and principles don’t change.

God’s plan of salvation for the ancient Jew, and His plan of salvation for the Christian are based on the same principle. The Hebrew writer reveals it to us, “Without the shedding of blood there is no forgiveness of sins” (Heb. 9:22). Under both covenants the penalty of sin is death, and under both covenants a substitutionary sacrifice was used to take away the sins of the penitent believer. In both covenants the substitutionary sacrifice is enacted through the faith of the individual.

For the reasons given above, Paul speaks of the Old Law as a tutor “to bring us to Christ” (Gal. 3:24). Similarly, the Hebrew writer tells us the law was “a shadow of the good things to come, and not the very image of the things” (Heb. 10:1). The OT was revealed to us because its teachings are pertinent to the understanding of God’s eternal plan. The New Testament reveals the fulfillment of God’s eternal plan through His Son. If we do not know the Old Law, we severely hinder our knowledge of God’s eternal plan.

For example, without a proper knowledge of the Old Testament, phrases such as, “Behold the Lamb of God who takes away the sins of the world” (John 1:29), lose their significance. We would be forced to ask, “what does John mean, the ‘lamb of God?’ What does a lamb have to do with taking away sins?” But familiarity with the Old Law immediately causes one to compare the innocent, sinless life of Christ, to the perfect, unblemished sacrificial lamb. Furthermore, we can conclude that Christ who was a sinless human being, not a mere animal, provided a more perfect sacrifice—the perfect sacrifice. He was like us. His blood could rightfully be exchanged for ours. Animal sacrifice couldn’t complete the job, but it does help us understand why Christ had to shed His blood (Lev. 17:11).

The book of Hosea, which features a man of God buying back an adulterous wife to illustrate God’s great love for His wayward people, sheds light on the concept of man’s reconciliation to God. God, through His Only Begotten Son, redeemed us. God bought back those who believed in His Son, and restored His relationship with them. Hosea powerfully portrays the mercy and the grace of God. Would we know God loves us without Hosea’s prophecy? I’m not sure I can answer that, but I do know this: Hosea helps us more closely identify with God’s feeling of love by illustrating it to us in the human marriage relationship. The relationship we ruined by infidelity, God restored by unconditional love. We need to read the Old Testament.

Please do not cast aside the first 39 books of the Bible, because they “do not apply to us today.” If you will carefully read the Old Testament, the New Testament will shine in a way you have never seen it shine before. Understanding the relationship between the Old and New Testaments will not only strengthen your faith, but it will make Bible study a joyful and satisfying experience.