The primary purpose of the sermon on the mount was to explain in explicit and practical terms the quality of genuine righteousness of the citizens within the kingdom of heaven. It had to exceed the superficial and hypocritical righteousness of the Pharisees (Matthew 5:20).
Since Jesus—like Melchizedek—is the king of righteousness and peace (Hebrews 7:1-2) and high priest over the house of God, this is understandable.
Since the purpose of the appearance of God’s grace via His Son and the gospel is to deny ungodliness and worldly lusts and live soberly, righteously, and godly in this present age (Titus 2:11-12), this is understandable.
Since the focus of the kingdom of God is not eating and drinking but righteousness, peace and joy in the Holy Spirit (Romans 14:17), this is understandable.
In addition to being a thorough instruction in righteousness, Jesus’ sermon on the mount had another result: “the people were astonished at His teaching” (Matthew 7:28).
It is an astonishing sermon:
- Because of its brevity. There is not a single unnecessary jot or tittle. To read aloud, the sermon would take the average reader less than thirty minutes to complete. This astonishing sermon most brilliantly demonstrates the timeless adage that “a sermon does not have to be eternal to be immortal”.
- Because of its purity. At no point in this sermon is there the blot of any slight compromise with sin. Murder and the angry hatred which spawns it are condemned. Adultery and frivolous divorce—engendered by a lustful heart—are all condemned. False oaths and the lack of integrity which produces it are condemned. Personal vengeance and the resentful bitterness which generates it are condemned. Prejudice and the lack of character which begets it are condemned. This astonishing sermon contains the highest standard of righteous purity humanly possible.