One feature of the Sermon on the Mount that jumps off the page is the juxtaposition of the phrases “You have heard” and “But I say” — without a deep study of the text one might think that Jesus is changing or contradicting the Law with which the Jews were so intimately familiar. However, Jesus reminds us at the beginning of the Sermon on the Mount, ” Do not think that I came to abolish the Law or the Prophets; I did not come to abolish, but fulfill.”
What becomes very clear is that Jesus’ teaching cuts to the heart of the matter. He is not providing “new” teaching, but rather providing new insights into the teaching that God had already provided. As Kay Arthur states, ” Jesus was concerned for his disciples…He wanted them to understand the narrowness of the way that leads to life, the gravity of not just hearing what He said but living accordingly. It was with these concerns on His heart that He preached the Sermon on the Mount.” ( p. 78)
The other key feature of Jesus’ instruction in the Sermon is that there is always an “action” piece to the teaching. We are never simply given counsel or admonition, but He consistently tells us how we can put the teaching into action.
Concerning murder (Matthew 5:21-26), Jesus expands the Law by saying that even a person who is angry, or calls his brother good for nothing (Raca) or a fool is “guilty enough to go into the fiery hell.” How do we put this into practice? Before bringing our offering to God we must go to our brother and reconcile. In other words, we have to initiate making amends with the one who has something against us.
Concerning adultery (Matthew 5:27-32), Jesus expands the Law by saying that even a person who “looks on a woman” in lust has committed adultery with her in his heart. How do we put this into practice? “Tear out your eye…cut off your hand” — take physical control of yourself and make the necessary changes to rid adultery from your life. Do not continue or make a practice of “looking” and do not let your heart follow your eyes.
Concerning vows (Matthew 5:33-37), Jesus expands the Law by saying that we should make no oaths at all. How do we put this into practice? Let our yes be yes and our no be no — don’t say we will do something we won’t, don’t over-commit, be honest with our obligations. When the intent of our heart is to not keep a promise, but we make the promise anyway, we profane the name of God. As David prayed, “Set a guard, O LORD, over my mouth; Keep watch over the door of my lips.” (Psalm 141:3)