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The Sermon on the Mount: Kingdom Ethics

The Sermon on the Mount represents Jesus' most comprehensive teaching on Kingdom ethics and righteous living. In this remarkable discourse, found primarily in Matthew chapters 5-7, Jesus establishes the principles that should govern the lives of His followers and reveals how He fulfills the Old Testament Law.

The Context of the Sermon

The Sermon on the Mount begins with Jesus going up on a mountainside, reminiscent of Moses receiving the Law on Mount Sinai. However, rather than replacing the Law, Jesus clarifies His purpose in Matthew 5:17: "Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them."

"You Have Heard... But I Say to You"

Throughout the Sermon on the Mount, Jesus employs a distinctive teaching pattern that reveals the deeper meaning of God's Law. He repeatedly uses the phrase "You have heard that it was said" followed by "But I say to you" (But I Say to You…, 4:33). This pattern appears in:

Jesus wasn't contradicting the Old Testament teaching, but rather addressing the rabbinic interpretations that focused solely on external compliance while ignoring the heart (But I Say to You…, 6:08). The Pharisees and scribes were concerned with outward appearances, but Jesus reveals that God's law penetrates to the spirit and intent behind our actions.

The Deeper Meaning of Murder

A striking example of this principle appears in Jesus' teaching about murder. While the religious leaders believed keeping the sixth commandment simply meant not physically killing someone, Jesus reveals the profound depth of God's law (But I Say to You…, 7:29):

"But I say to you that if you are angry with a brother or sister, you will be liable to judgment; and if you insult a brother or sister, you will be liable to the council; and if you say, 'You fool,' you will be liable to the hell of fire." - Matthew 5:22

Jesus describes three escalating levels of heart-murder:

  1. Brooding anger - The simmering, grudge-holding kind of anger that refuses reconciliation (But I Say to You…, 9:01)
  2. Slander and derision - The word "raca" encompasses insulting, slandering, and deriding others (But I Say to You…, 9:52)
  3. Calling someone a fool - The Greek word "moros" (from which we get "moron") was used to denote someone as dull, stupid, or godless (But I Say to You…, 11:04)

This teaching reveals that we can murder people with our anger and words, even when they walk away physically unharmed (But I Say to You…, 8:17). As 1 John 3:15 confirms: "All who hate a brother or sister are murderers, and you know that murderers do not have eternal life abiding in them."

The Beatitudes: Characteristics of Kingdom Citizens

The Sermon begins with the Beatitudes (Matthew 5:3-12), which describe the character and blessings of those who belong to God's Kingdom:

  • The poor in spirit - Those who recognize their spiritual bankruptcy
  • Those who mourn - Those who grieve over sin and its effects
  • The meek - Those who are gentle and humble
  • Those who hunger and thirst for righteousness - Those who deeply desire God's righteousness
  • The merciful - Those who show compassion to others
  • The pure in heart - Those whose motives are sincere (Pure in Heart, 14:22)
  • The peacemakers - Those who work to reconcile relationships
  • Those persecuted for righteousness - Those who suffer for doing right

The Challenge of Loving Our Enemies

One of the most radical aspects of Jesus' teaching comes in His call to love our enemies (Matthew 5:44). Jesus confronts the rabbinic addition to Scripture that taught "love your neighbor and hate your enemy" - an addition not found in God's Word (Love Who?, 3:43).

Jesus challenges His listeners with penetrating questions: "If you love those who love you, what reward do you have? Do not even the tax collectors do the same?" (Love Who?, 7:01). He points out that even the most despised people - tax collectors and Gentiles - practice reciprocal love (Love Who?, 8:31).

The standard Jesus calls us to is agape love - selfless, sacrificial love that acts for the benefit of others regardless of their response to us (Love Who?, 15:31). This love is demonstrated through action, as seen in all fifteen characteristics of love in 1 Corinthians 13, which are expressed as verbs (Love Who?, 16:07).

The Golden Rule: More Than Reciprocity

Jesus also teaches the Golden Rule: "Do to others as you would have them do to you" (Luke 6:31). While similar principles exist in other religions and philosophical systems, they are typically expressed in the negative - what not to do. Jesus uniquely states it positively, calling for active engagement rather than mere avoidance (The Golden Rule, 5:24).

The temptation is to twist the Golden Rule into mere reciprocity - "do to others as they do to you" (The Golden Rule, 8:59). But Jesus calls us to something higher: loving and serving others "expecting nothing in return" (The Golden Rule, 14:22), just as the Good Samaritan demonstrated selfless love to someone in need.

Our Need for Grace

Jesus' teaching in the Sermon on the Mount reveals that we all fall short of God's perfect standard. We are all murderers in our hearts, breaking both the letter and spirit of God's law (But I Say to You…, 12:43). Like the Pharisees, we can be concerned with external appearances while our hearts remain full of "hypocrisy and lawlessness" (Matthew 23:27-28).

Scripture reminds us that we are born as enemies of God (Romans 5:10), yet God loved His enemies - us - by sending His Son to bear our sins on the cross (Love Who?, 16:14). This recognition of our sinfulness points us to the sweetness of God's grace in Jesus Christ (But I Say to You…, 20:43). Christ bears all our sin—including our murdering sin—when He goes to the cross. He provides the word of absolution, rises from the tomb, and calls us His own in the waters of baptism.

As 1 Peter 3:18 reminds us: "For Christ also suffered for sins once for all, the righteous for the unrighteous, in order to bring you to God." Because of Christ's sacrifice, each day is truly new, and when we fall short in our struggle with sin, we are met with the grace of God in Jesus Christ (But I Say to You…, 22:46).

Living as Kingdom Citizens

The Sermon on the Mount calls us to live as citizens of God's Kingdom, recognizing that true righteousness comes not from external compliance but from hearts transformed by God's grace. We are called to be salt and light in the world (Matthew 5:13-16), seeking first God's Kingdom and His righteousness (Matthew 6:33), and building our lives on the solid foundation of hearing and doing Jesus' words (Matthew 7:24-27).

When Jesus calls us to "be perfect, therefore, as your heavenly Father is perfect" (Matthew 5:48), this comes to us first as law, revealing how far we fall short. But it also comes as gospel, because God looks at us through the lens of Jesus Christ's shed blood (Love Who?, 18:24). We have been made perfect, clothed in Christ's righteous garment in the waters of baptism, and God sees us through the perfection of Christ.

Through Christ's perfect fulfillment of the Law and His sacrificial death, we find refuge from the Law's condemnation and are saved by grace through faith alone. As the Lutheran theologian Matthias Loy wrote: "To Jesus we for refuge flee, who from the curse has set us free, and humbly worship at his throne, saved by his grace through faith alone" (But I Say to You…, 23:51).