Mark 6:18 Commentary: The Lawful Word of a Prophet

Herod Antipas ruled Galilee and Perea as a tetrarch under Roman authority. He had divorced his first wife, the daughter of King Aretas of Nabatea, to marry Herodias. Herodias had been married to Herod's half-brother Philip (or perhaps another brother named Herod; Josephus records both). In either case, the marriage violated the prohibition in Leviticus against taking a brother's wife while the brother lived. The Jewish law was clear, and Herod, as a ruler over Jewish subjects, was expected to uphold it.

John the Baptist was imprisoned in the fortress of Machaerus, east of the Dead Sea. There, Herod would occasionally visit him. John's words were not whispered in private but spoken directly to the tetrarch's face. This was a deliberate act of prophetic courage, a direct confrontation with royal sin, without fear of the consequences (Barnes). The phrase “the was saying” (imperfect) indicates that John kept speaking this truth even when he knew it could cost him his life.

Herodias, the injured party in the story, held a bitter grudge. John's public condemnation of her marriage made her a target of shame. She would eventually manipulate Herod into beheading John, using her daughter's dance as a tool. Herod himself was conflicted: he feared John, knowing him to be righteous and holy, and enjoyed hearing him speak, yet he would not repent (Barnes).

The supplied sources note no significant textual variants for Mark 6:18. The verse is stable in the manuscript tradition. The only minor variation among translations is between simple past (“said”) and past progressive (“had been telling” or “was saying”), which reflects the Greek imperfect tense elegen rather than a textual difference.

This verse has been used throughout church history to affirm the supremacy of God's law over king and emperor. Early church writers, including Tertullian and Jerome, cited John's example when urging Christians to speak against immorality in the imperial household. During the Reformation, John's courage was held up as a model for preachers who faced hostile rulers. The story of John and Herodias also inspired many artistic works, from medieval mystery plays to Renaissance paintings, often emphasizing the contrast between the prophet's faithfulness and the court's corruption. In more recent centuries, the verse has been quoted in debates about marriage, divorce, and the limits of political authority over conscience.

Three-point outline

1. The law of God stands above every ruler. John did not appeal to public opinion or personal offense, he appealed to Scripture. Leviticus 18:16 and 20:21 define the boundary. No king is above God's moral law.
2. Prophetic witness costs something. John's bold word cost him his freedom and eventually his head. Yet he did not stop speaking. His faithfulness models the calling of every messenger of God: speak the truth, even when it is dangerous.
3. A conscience can hear truth and still reject it. Herod feared John, did many things gladly, yet did not break with his sin. A stirred conscience is not the same as repentance (Barnes).

Five-point outline

1. John's boldness: He spoke to Herod’s face, not behind his back (Matthew 14:4).
2. The specific sin: Marrying a brother's wife while both formerly married parties still live.
3. The legal basis: Leviticus 18:16 and 20:21.
4. Herod's response: Fear, fascination, and partial obedience, but not repentance.
5. Herodias' revenge: A grudge nursed into murder (Mark 6:19).

Illustration hooks

• A whistleblower in a company who refuses to sign off on fraudulent accounts because the law is clear. The personal cost is real.
• A pastor who preaches on marriage and divorce knowing it will touch raw wounds in the congregation, and may cost him relationships.
• A politician who is told plainly that a certain policy will harm the poor, and who must choose between public favor and moral duty.

Questions your congregation is asking

• If I know someone is in a sinful situation, when and how should I speak?
• Why did Herod keep listening to John if he would not obey? What does that say about my own heart?
• Is it ever right to confront sin publicly, or should it always be private?

This verse stands at the hinge of the story of John the Baptist's death. It shows us the kind of truth that leads to martyrdom. As you discuss, think about what John risked, and what he gained.

Discussion questions

1. What exactly did John say? (Read verse 18 aloud in your version.)
2. Why was it unlawful for Herod to have his brother’s wife? Look at Leviticus 18:16 and 20:21.
3. What does the imperfect tense of “had said” (or “was saying”) tell you about how John delivered this message?
4. How did Herod respond to John’s message? (See verses 20, 26.) Was Herod’s fear of John the same as repentance? Why or why not?
5. Herodias wanted John dead. What does this conflict between a woman's pride and a prophet's word teach about the cost of speaking truth?
6. When have you faced a situation where speaking the truth clearly would cost you something? How did you respond?
7. What can we learn from John’s example about balancing boldness and grace in our own confrontations with sin?