Matthew 5:17-20: Jesus and the Law

How to Use This Commentary

Matthew 5:17–20 is one of the most important passages in the entire Sermon on the Mount. Read it in three movements: (1) Jesus and the Law (v.17), (2) the authority of Scripture (v.18–19), and (3) the kind of righteousness God requires (v.20).

Key: This passage explains how everything Jesus teaches next should be understood.

This is where everything sharpens.

Jesus has just said you are salt and light (Matthew 5:13–16).

Now the question becomes:

👉 By what standard do we live?

Do we follow the Old Testament? Has Jesus replaced it? Do we make our own rules?

Jesus answers clearly:

👉 God’s Word still stands—and you need a righteousness deeper than you ever imagined.

A Quick Look: Matthew 5:17–20

Big idea: Jesus did not abolish God’s law—He fulfilled it and calls us to true righteousness that comes from God, not ourselves.

Why this matters: Many people think Christianity lowers God’s standards. Jesus says the opposite—it reveals how high they truly are.

Key truth: External religion is not enough. God requires a transformed heart.

Bottom line: You don’t need better rule-keeping—you need a new kind of righteousness.


A Simple Explanation (Matthew 5:17–20)

“I did not come to abolish…but to fulfill” (v.17)
Jesus is not canceling the Old Testament—He is completing it.
Meaning: Everything in Scripture points to Him.
Application: The Bible still matters—all of it.

“Not the smallest letter…” (v.18)
God’s Word is permanent and unchanging.
Meaning: Every detail of Scripture is trustworthy.
Application: You don’t pick and choose what to obey.

“Whoever relaxes…will be least” (v.19)
How you treat God’s Word matters.
Meaning: Minimizing Scripture weakens your life and influence.
Application: Take every part of God’s Word seriously.

“Unless your righteousness surpasses…” (v.20)
Religious effort is not enough.
Meaning: The Pharisees looked righteous—but weren’t truly righteous.
Application: God wants heart transformation, not just outward behavior.

Bridge: This passage shows us that the issue isn’t whether we follow the law—it’s whether we have the kind of righteousness only Jesus can give.


A Deeper Dive: Jesus, the Law, and True Righteousness

1) The Central Question: What is the Standard?

Jesus addresses the foundation of truth, morality, and righteousness.

Insight: Without an absolute standard, society collapses into relativism—truth becomes preference instead of reality.

2) “Do Not Think…” — Correcting a Misunderstanding

Many assumed Jesus came to replace or reject the Old Testament.

Insight: Jesus challenges that assumption immediately—He is not opposing Scripture but affirming it fully.

3) “Abolish” vs. “Fulfill” (Greek Insight)

  • kataluō (abolish) → to destroy, dismantle, nullify
  • plēroō (fulfill) → to complete, bring to full expression

Meaning: Jesus didn’t tear down the law—He completed its purpose.

4) How Jesus Fulfills the Law

Jesus fulfills the law in three major ways:

  • Perfect obedience → He kept it completely
  • Prophetic fulfillment → He is what it pointed to
  • Final sacrifice → He completed its requirements

Insight: The Old Testament is not replaced—it is completed in Christ.

5) The Three Aspects of the Law

  • Moral law → reflects God’s character (still binding)
  • Ceremonial law → fulfilled in Christ’s sacrifice
  • Judicial law → fulfilled in Israel’s role

Key insight: The moral law remains because God’s character does not change.

6) The Permanence of Scripture (v.18)

Jesus says not even the smallest letter (Greek iōta, Hebrew yod) or stroke will pass away.

Insight: Scripture is authoritative down to the smallest detail.

7) The Danger of Minimizing God’s Word (v.19)

To “relax” or “annul” commands means treating them as optional.

Insight: How you view Scripture determines your spiritual depth and influence.

8) The Failure of Pharisee Righteousness (v.20)

The Pharisees’ righteousness was:

  • External → focused on behavior, not the heart
  • Partial → emphasized minor rules, ignored major ones
  • Redefined → adjusted God’s standards
  • Self-centered → aimed at personal glory

Insight: Religious activity without heart transformation is not true righteousness.

9) The Righteousness God Requires

God requires perfect righteousness (cf. Matthew 5:48).

Problem: No one can achieve this on their own.

10) The Righteousness God Gives

The solution is not trying harder—but receiving righteousness through Christ.

Insight: The law reveals sin, but Christ provides righteousness.

Teaching line: The law shows you your need—Jesus meets that need.

11) The Flow of the Sermon

  • Beatitudes → heart condition
  • Salt & Light → influence
  • 5:17–20 → authority & foundation

👉 Everything that follows (anger, lust, etc.) flows from this foundation.

Deep Dive Summary:
  • Jesus fulfills—not abolishes—the law
  • Scripture is fully authoritative
  • External religion is insufficient
  • God requires perfect righteousness
  • Only Christ provides that righteousness

Bottom Line (Matthew 5:17–20)

Jesus didn’t lower God’s standard—He fulfilled it and offers you the righteousness you could never achieve on your own.


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