There are many Christians who struggle with understanding the Old Testament in the Bible and how it connects with the Gospel, or the New Testament. Consequently some Christians discount the Old Testament entirely and claim that all that matters is the Gospel and what Jesus said and did. Some go so far as to say that the Old Testament doesn’t apply anymore and was written for a different time, a different culture and a different purpose. In other words, the Old Testament is not relevant to the Christian faith and can simply be discarded as some Jewish history and a bunch of highly questionable stories.
But is that really true? Can we “unhitch” the Old Testament from the gospel as one prominent American preacher has suggested? Is the Law contained in the Old Testament no longer applicable for Christians? Are Christians faced with choosing to adhere to the Law or the Gospel?
The Christian faith is based solely on the work of Jesus on the cross. But it is also built on the truth of the Bible. While the Bible is not the source of our salvation (faith in Jesus is), it is the inerrant and inspired Word of God that was written down for our benefit so that we can know God more deeply and accurately. The Bible contains the history of God’s relationship to man and his prior covenants with the Jewish people (Old Testament) as well as his covenant with all people through Jesus Christ (New Testament). We cannot separate the two parts of the Bible because they reinforce each other and work together for our understanding. Therefore, we must seek to understand how they both apply to us as Christians today.
As Christians, it is true that salvation comes through faith in Jesus and not adherence to the Law (John 3:16). Paul said that the Law shows us our sin (Romans 3:20) and that we cannot be saved through the Law because we cannot possibly keep it (Romans 7:18). Jesus said in Matthew 5:17 that the Law will never pass away, and that He is the fulfillment of the Law. In other words, Jesus did what we could not do (complete obedience to the Law) and gave His life so that we might be free from the Law. So to understand why Jesus came and what He did on the cross we must know the Old Testament to put Jesus into proper context. For without the Old Testament how could we possibly understand why we need Jesus for salvation?
So then, what is the purpose of the Law for Christians and why should we read the Old Testament?
First, as Paul said, the purpose of the Law is to show us our sin. What Paul is referring to is God’s Moral Law such as the 10 Commandments, laws on sexual behavior, etc. (The Jews added many civil and ceremonial laws on top of God’s Moral Law so it’s important to recognize the difference. Jesus freed us from the civil and ceremonial laws, but not God’s moral Law.) In order to believe in Jesus as our savior, we must first acknowledge that we are sinners (breakers of God’s Moral Law) and in need of a savior. John 1:9 reminds us that “if we say we have no sin, the truth is not in us.” Second, Paul also tells us that “the Law is holy, righteous and good” (Romans 7:12) and is what God expects us to try and adhere to. While the Law is no longer the standard for salvation, it is still the standard for our behavior. Third, the Old Testament documents what happens to us when we disobey God and try to do things on our own (Judges 21:25). Fourth, the Old Testament reveals God’s plan of salvation through the prophecies about Jesus that are ultimately confirmed in the birth, life, death and resurrection of Jesus in the New Testament (Isaiah 9:6-7 & Isaiah 53).
So then, how are we to understand the Law and the Old Testament in light of the Gospel?
As for the Law, it is there to remind us of God’s standard for living righteous and holy lives. Just because we can’t keep the Law does not mean it should be disregarded or not obeyed. Obeying the Law does not save us or cause God to love us more. We should obey His Law because of what God has done for us (forgiveness) and to honor Him and bring him glory! And when we transgress that Law, we are called to repent and seek His forgiveness, which He promises to all who seek Him.
As for the Old Testament, can we really just toss it out or disregard some of its contents because it may not seem to make sense to us today? Absolutely not! Just because we may not understand God’s Word in the Old Testament does not mean it either is not true or not applicable today. Jesus often quoted the Old Testament and confirmed its truth. So if He believed it was true and God’s Word, so should we! He also said that the Old Testament is about Him and speaks of Him (Luke 4:16-21). Furthermore, the Old Testament contains many historical events that must be read in light of the language it was written in, the prevailing culture, the geography, the economy, and the political structure at the time in order to better understand what God is trying to tell us or reveal to us about His character and nature.
So for man to somehow claim that certain parts of the Bible don’t matter anymore is the height of arrogance and man placing himself above God. It is either God’s Word or it is not God’s Word. We can’t pick and choose which parts we accept or believe and which parts we don’t. We are not that intelligent! (Isaiah 55:9) As humans, and God’s creation, all we can do is seek to understand God through His Word and through the guidance of the Holy Spirit.
So the Christian faith is not dependent upon obedience to the Law. But it is also not about just saying we are Christians and doing as we please. Being a believer in Jesus (a Christian) means that we put our faith in Jesus for our salvation AND do our best to obey God’s commands and live a holy and righteous life. In other words, it is not Law or Gospel, it is Law AND Gospel.
So let us show our gratitude to God for sending Jesus to the cross for our salvation by trying to live God honoring and pleasing lives. As the Holy Spirit has brought us to faith through the Gospel (1 Corinthians 2:10) the Holy Spirit will also help us be obedient to God’s Law (Galatians 5:16).