The Sermon on the Mount: The Antitheses (Matthew 5:21-48)
The Sermon on the Mount, recorded in Matthew chapters 5-7, stands as the most profound and foundational teaching ever delivered by Jesus Christ. It is not merely a collection of moral aphorisms, but a comprehensive exposition of the righteousness required for entry into and life within the kingdom of heaven. Central to this discourse are the "antitheses" found in Matthew 5:21-48, where Jesus repeatedly declared, "Ye have heard that it hath been said... But I say unto you." This striking phrase marks a pivotal moment in divine revelation, as the Son of God, with unparalleled authority, expounded the true spirit and intent of God's Law, contrasting it sharply with the superficial interpretations prevalent in His day.
Jesus' Divine Authority: "But I Say Unto You"
For centuries, the Jewish people lived under the Mosaic Law, interpreted and taught by scribes and Pharisees. Their authority was rooted in tradition and the letter of the Law. However, Jesus did not present Himself as another interpreter, but as the very Lawgiver. His repeated declaration, "But I say unto you," was a direct assertion of divine authority, transcending and fulfilling the Old Covenant. He was not abrogating the Law, as He explicitly stated in Matthew 5:17, "Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil." Instead, He unveiled its ultimate purpose and profound spiritual depth, revealing that God's demands extended far beyond outward conformity to the heart's deepest intentions.
Beyond External Compliance: The Spirit of the Law
The righteousness taught by the scribes and Pharisees focused predominantly on external obedience. As long as one did not commit the physical act of murder or adultery, they were considered righteous in that aspect. Jesus, however, shattered this superficial understanding, demonstrating that sin originates in the heart and mind. He called His disciples to a righteousness that "shall exceed the righteousness of the scribes and Pharisees" (Matthew 5:20). This higher standard is not about earning salvation, which comes only through grace by faith in Christ, but about living out the transformed life that results from genuine faith. The antitheses reveal that true obedience involves internal purity and a radical commitment to God's holy character.
The First Antithesis: Murder (Matthew 5:21-26)
Jesus began by addressing the commandment, "Thou shalt not kill." While the Mosaic Law condemned the act of murder, Jesus delved into its root cause:
Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.
He revealed that unjustified anger, contemptuous words ("Raca" – empty-headed, worthless), and hateful insults ("Thou fool" – a moral reprobate, deserving of divine judgment) are tantamount to murder in the heart. These are the seeds from which physical violence springs. The call here is not merely to refrain from killing, but to cultivate a spirit of love and reconciliation, even to the point of seeking peace with an offended brother before offering sacrifice to God (Matthew 5:23-24).
The Second Antithesis: Adultery (Matthew 5:27-30)
Next, Jesus addressed the commandment against adultery:
Ye have heard that it was said by them of old time, Thou shalt not commit adultery: But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.
Again, Jesus moved beyond the external act to the internal desire. Lustful thoughts, even if never acted upon, are a violation of God's pure standard for sexuality. His radical instruction to "pluck out a right eye" or "cut off a right hand" (Matthew 5:29-30) was not a literal command for self-mutilation, but a stark metaphor emphasizing the absolute necessity of drastically severing anything, no matter how cherished or seemingly indispensable, that leads to sin. It underscores the severity of sin and the urgent need for internal purity.
The Third Antithesis: Divorce (Matthew 5:31-32)
Jesus then tackled the issue of divorce, which was loosely practiced under a rabbinic interpretation of Deuteronomy 24:1:
It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement: But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.
While Moses permitted divorce in certain cases due to the "hardness of your hearts" (Matthew 19:8), Jesus reaffirmed God's original, ideal design for marriage as a lifelong, indissoluble union established at creation (Genesis 2:24). He stated that divorce, except in cases of "fornication" (which often refers to persistent sexual immorality or unfaithfulness), leads to adultery for both parties. This teaching elevates the sanctity of marriage and condemns the casual dissolution of sacred vows.
The Fourth Antithesis: Oaths (Matthew 5:33-37)
The Mosaic Law permitted oaths to confirm truthfulness, but people had developed a system of swearing by various entities (heaven, earth, Jerusalem) to avoid accountability. Jesus condemned this practice:
Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths: But I say unto you, Swear not at all; neither by heaven; for it is God's throne: Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King. Neither shalt thou swear by thy head, because thou canst not make one hair white or black. But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.
Jesus' command is for radical truthfulness. Believers should be so consistently honest that their simple "yes" or "no" is entirely trustworthy, requiring no oath to validate it. Any attempt to use oaths to manipulate truth or avoid responsibility comes "of evil," revealing a heart not fully committed to integrity.
The Fifth Antithesis: Retaliation (Matthew 5:38-42)
The principle of "an eye for an eye, and a tooth for a tooth" (Exodus 21:24) in the Old Testament was intended to limit vengeance and ensure proportionate justice in a legal context, not to encourage personal revenge. Jesus, however, called for a higher standard in personal interactions:
Ye have heard that it hath been said, An eye for an eye, and a tooth for a tooth: But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also. And if any man will sue thee at the law, and take away thy coat, let him have thy cloak also. And whosoever shall compel thee to go a mile, go with him twain.
This teaching forbids personal retaliation and calls for a spirit of non-resistance to evil, not as a sign of weakness, but as a demonstration of Christ-like humility and trust in God's ultimate justice. Turning the other cheek, giving more than demanded, and going the extra mile are acts of sacrificial love that break the cycle of vengeance and reflect God's grace. It is a command to absorb injustice rather than perpetuate it.
The Sixth Antithesis: Love for Enemies (Matthew 5:43-48)
The climax of the antitheses is perhaps the most challenging and transformative:
Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you; That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
While the Old Testament commanded love for one's neighbor (Leviticus 19:18), the notion of hating one's enemy was a common, though unbiblical, human interpretation. Jesus demolished this, commanding unconditional love for enemies, including blessing those who curse, doing good to those who hate, and praying for persecutors. The motivation given is profound: to imitate the character of God, who extends common grace (sun and rain) to both the righteous and the unrighteous. This radical love is the distinguishing mark of true discipleship and culminates in the call to "Be ye therefore perfect, even as your Father which is in heaven is perfect" (Matthew 5:48). This perfection refers to completeness or maturity in demonstrating God's impartial and expansive love.
Conclusion: The Call to a Higher Righteousness
The antitheses of Matthew 5:21-48 are far more than a new set of rules; they are a revelation of God's holy character and His expectation for those who claim to be His children. Jesus did not lower the standard of the Law but elevated it, revealing its spiritual intent to transform the heart, not just modify external behavior. This divine standard makes it clear that true righteousness is beyond human capability apart from God's grace. It is a righteousness that can only be imputed through faith in Christ's perfect obedience and then empowered by the Holy Spirit within the believer. The Sermon on the Mount, particularly these antitheses, serves as a mirror reflecting our desperate need for a Savior, while simultaneously providing a challenging blueprint for a life truly consecrated to the Lord, demonstrating a love that reflects the very nature of God Himself.