“You have heard that it was said, ‘An eye for an eye and a tooth for a tooth.’ But I tell you not to resist an evil person.
Have you ever noticed in Jesus' Sermon on the Mount how he gently prepares his audience to accept something new? He lets them know who is blessed and why (Matthew 5:2-12). He then points out that if they follow Him, their behaviour will have to be different from those around them (Matthew 5:13-16). He enforces this by letting His listeners know that He is the fulfillment of the Law (Matthew 5:17-20). He then begins almost every topic with a variation of this set of words: "You have heard that it was said...but I tell you," referring to the laws of the Old Testament (Torah). In fact, for the rest of Matthew five, that is how he begins each topic. He did this to contrast the Pharisaical interpretation of the Law with His fulfillment of its intent. Jesus gets to the law's intent and, in the process, shows us what grace is all about.
The judicial penalty of "an eye for an eye and a tooth for a tooth" was common practice among the Hebrew nation and other nations of the time. The principle of retaliation was taken from Exodus 21:23-25 as a means to end disputes. But Jesus realized those who enforced these laws were using them as a license for revenge. But now, He was telling them a new way to live and the proper interpretation of Exodus 21:23-25. Rather than give in to anger and revenge against your neighbour, Jesus proposed a better way of how people were supposed to react when confronted with sin. Instead of responding with anger, violence or revenge, Jesus wanted people to follow His example and rise above it. Therefore we need to "overcome evil with good" (Romans 12:21). As God showed grace to us, we are to show grace to others. Jesus then gives us five examples of how we can extend grace to others.
Five Ways We Should Respond