[Excerpt from our book Your Identity in Christ]
The real difference between the Old and New Covenants isn’t just the Bible’s title page between Malachi and Matthew; rather, the dividing line lies at the death and resurrection of Jesus. Many people get confused because they mistakenly think Jesus’s entire earthly ministry comes under the New Covenant. In truth, Jesus was “born under the law” and ministered primarily to Jews still living under the Old Covenant. So, not everything Jesus said was directly meant for us as New Covenant believers today.
To properly divide the Word in the gospels, we need to ask: Who was Jesus speaking to? When was he speaking to them? And what was he talking about? Was Jesus addressing Jews under the Law and elevating the Law to impossible heights they hadn’t considered before? Or was he talking to his disciples about the coming kingdom? This is so important. If we interpret a message delivered to first-century Jews under the Law, and before the cross, as a message to Christians after the cross, we are going to get very confused when we read Paul’s letters about grace. To reconcile Jesus’ “Law talk” with Paul’s “Grace talk” requires theological contortions that are likely to leave you with a headache at best and throwing in the towel at worst.
A primary example is the Sermon on the Mount. This sermon was Jesus’ extraordinary exposition of the true, unattainable standard of the Mosaic Law, designed to expose the self-righteousness of His listeners. Remember, he was talking to Jews under the Law, not to Christians. Jesus was not espousing a better self-improvement program; he was articulating just how impossible it was for them to keep the whole law.
The sermon begins with the Beatitudes, which are not a to-do list for earning blessings but a declaration of what would be fulfilled in Christ. Jesus is the one who satisfies the “hunger and thirst for righteousness” (Matthew 5:6). Similarly, when Jesus calls his audience the “salt of the earth” and “light of the world” (Matthew 5:13-14), he is referencing Israel’s specific role under the Old Covenant, including their “covenant of salt” (Leviticus 2:13-14; Numbers 18:19; 2 Chronicles 13:5). In the New Covenant, it is Jesus who is “the light of the world” (John 8:12), and believers are “children of light” in him (1 Thessalonians 5:5; 1 Peter 2:9), which is a different identity.
Jesus declares he came not to abolish the Law but to fulfil it:
Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them. For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished. (Matthew 5:17-18, ESV).
He then delivers the sermon’s first major blow: “unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven” (Matthew 5:19-20). This was no doubt shocking to the Jewish audience, who viewed the Pharisees as the pinnacle of righteousness, and forced them to realise that their own efforts were completely insufficient. Jesus then magnifies the Law’s true internal demands. He equates murder with anger (Matthew 5:21-22) and adultery with lustful intent (Matthew 5:27-28), mentioning Old Covenant rituals like offering gifts at the altar (Matthew 5:23-24) to ground his teaching in their current reality.
Jesus’s commands to tear out a sinning eye or cut off a hand (Matthew 5:29-30) should not be dismissed as mere metaphor. To do so is to cherry-pick which parts of the sermon to take seriously. Instead, Jesus was demonstrating the absurd and impossible lengths to which the Law’s demands would require, showing the utter hopelessness of that system. Even if they did pluck out the sinning eye and hand, there would still be something in their heart and mind that was unrighteous, and that would fall short of perfection. Somewhere along the line, they wouldn’t turn the other cheek, or give up their coat, or love their enemies. And that was the whole point of the Law – it taught that sin was innate and that self-effort was hopeless to resolve the issue. The entire message culminates in the crushing final command of the chapter: “You therefore must be perfect, as your heavenly Father is perfect” (Matthew 5:48). This was the summary of the Law’s requirement: absolute perfection.
Ultimately, Jesus’ sermon on the mount served the true purpose of the Law, as Paul explained in Romans chapter 3:
Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin. (Rom 3:19-20, ESV)
By showing the Law’s impossible standard, Jesus silenced all human boasting and clearly demonstrated that “by works of the law no human being will be justified,” pointing us all to the absolute necessity of a Saviour.
