The Ten Commandments primarily focus on behaviors, while the Sermon focuses on desires.
According to the Sermon, our goodness needs to be better than that of the teachers of the law and Pharisees. They depended on their work, their behavior. But actions can be deceiving. If we don’t commit a crime because of fear to get caught, what if we wouldn’t get caught, would we commit the crime?
Christ focuses on our hearts, our desires. Actions arise from them. For example, envy, the green-eyed monster, led to Abel killing Cain, the first murder in the Bible.
Hate can lead to murder. So, don’t even call someone a brainless idiot, a worthless fool (1 John 3:15; 1 John 2:9; and Matthew 5:22).
Lustful thoughts can lead to adultery. So, guard our minds (Matthew 5:28).
“An eye for an eye” should be the job of the government. Police and the court of law are established by God to administer justice, matching punishments to the offense so as to frighten criminals and purge evil (Romans 13:1-2; and Deut 19:18-21). The Bible even uses armor as analogies, and some attributes of soldiers as models (Ephesians 6:10-17; and 2 Timothy 2:3-4).
There are times to use force and exercise our rights. For example, Christ administered justice with physical force in a temple (John 2:13-16). In time of danger, Christ told his disciples to get swords to defend (Luke 22:36-38). Paul exercised his rights as a Roman citizen (Acts16:35-40). But beware of the consequences. Living by the sword dies by the sword (John 18:10-11; and Matthew 26:52).
There are times to take the unreasonable hit, turn the other cheek, and go the extra mile, such as for God’s kingdom, salvation of the soul. Note that insults are difficult to bear. Even Paul could flare up (Acts23:1-5). But our endurance can turn enemies into friends, better yet, into followers of Christ.
Christ is our model. He loved His enemies, as shown by His crucifixion. Christ’s behavior even converted the hardcore criminal crucified next to Him (Luke 23:39-43).
Christ focuses on our hearts. He wants us to be perfect like our heavenly Father. So, do whatever is necessary to maintain a pure heart (Matthew 5:29-30, 48). But more importantly, rely on our Father in heaven to do so (Hebrews 12:1).
Summary of a sermon by Greg Laurie