We are now entering the section of Scripture where Jesus is beginning to explain to us what He means by having a righteousness deeper than that taught by the religious leaders of the day (Matthew 5:20). These words of Jesus are vital for us to understand as Christians.
One of the misunderstandings of the doctrine of salvation by grace alone is that we are no longer living under the law. Well that is true if you are talking about living under the Old Testament dietary and ceremonial law that has been fulfilled by The Lord Jesus Christ (Colossians 2:16-17; Hebrews 7:11-10:14; Galatians 2:16, 3:3-14). But it is not true if you interpret grace as meaning that we can live however we want. Paul dealt with this misunderstanding in his letter to the Romans when he wrote, “What shall we say then? Shall we continue in sin that grace may abound? Certainly not! How shall we who died to sin live any longer in it?” (Romans 6:1,2) And in Paul’s pastoral epistle to Titus, The Holy Spirit clearly reveals that “the grace of God that brings salvation has appeared to all men, teaching us that, denying ungodliness and worldly lusts, we should live soberly, righteously, and godly in the present age.” (Titus 2:11,12)
The grace of God does not eliminate the call to living holy; instead it elevates it to its rightful place. What Jesus does in this section of the Sermon on the Mount is drive home the true meaning of the law from the outward actions to the motives and attitudes of the heart. Jesus will teach us that murder is not only something that is done with a gun, but with a bitter or resentful attitude. He will also go on to tell us that adultery is not just a physical sexual act outside of the covenant of marriage, but a lustful desire to be with someone who is not your spouse (Matthew 5:21-28). If what Jesus is saying is true (and of course it is!), the obvious conclusion is that we are all sinners and in need of the grace of God! “Therefore the law was our tutor to bring us to Christ, that we might be justified by faith.” (Galatians 3:24)
Yes, the law was meant to drive us to the saving grace of Christ. But the grace of Christ was not meant to produce rebels whose faith runs contrary to the moral law of God (Romans 6:11-18). Jesus Christ is the believer’s righteousness (Romans 10:1-4), and the evidence that He is dwelling in our hearts is that we will seek to please Him and bring Him glory in not just what we do, but how and why we do it.