Matthew 17:21 is “missing” in many modern Bible translations because most scholars believe it was not part of Matthew’s original Gospel text but a later addition copied from the parallel passage in Mark 9:29. Modern translations follow the earliest and most reliable Greek manuscripts, where this verse does not appear.

What the “missing” verse says

In Bibles that include it (often KJV, NKJV), Matthew 17:21 reads roughly:

“But this kind does not go out except by prayer and fasting.”

It comes right after Jesus explains why the disciples could not cast out a demon, and it emphasizes prayer and fasting as the means for dealing with particularly stubborn demonic cases.

In many newer translations (NIV, ESV, CSB, etc.) you will see:

  • Matthew 17:20
  • Then it jumps straight to Matthew 17:22
  • With a footnote saying something like “Some manuscripts add verse 21: ‘But this kind does not go out except by prayer and fasting.’”

Quick Scoop: Why is Matthew 17:21 missing?

1. Textual criticism: checking the oldest manuscripts

Scholars compare thousands of ancient Greek manuscripts to see what the original text most likely said. This field is called textual criticism.

Key points:

  • The earliest and best manuscripts of Matthew (such as important 4th–5th century codices) do not have Matthew 17:21.
  • The wording “this kind does not go out except by prayer and fasting” does appear clearly in Mark 9:29, the parallel account of the same event.
  • Many scholars think a scribe, wanting Matthew to match Mark, copied the phrase from Mark into Matthew—probably with good intentions (harmonizing the Gospels).

Because of that:

  • Older translations (like KJV) are based on later manuscripts that already had this harmonized verse in Matthew.
  • Newer translations use earlier manuscript families and therefore either:
    • Move the verse to a footnote, or
    • Omit the verse number entirely (jumping 20 → 22) with a textual note.

2. So was a verse “deleted”?

This is where a lot of online debate and forum discussion comes in.

  • Some Christians (especially in King James Only circles) say: “Modern Bibles removed Matthew 17:21, and that’s dangerous because it downplays prayer and fasting.”
  • Textual scholars answer: “No one deleted it from the Bible today; rather, we discovered that it was not in the earliest copies , so we’re being honest about what Matthew originally wrote.”

From the academic side:

  • There is no obvious reason early scribes would want to remove a verse that strongly encourages prayer and fasting; it’s spiritually rich and doctrinally safe.
  • There is a very clear reason a scribe might add it: to align Matthew more closely with Mark and clarify that some demons require extra spiritual discipline.

So modern editors generally conclude:

  • Matthew 17:21 is most likely not original to Matthew,
  • But it accurately reflects Jesus’ teaching as preserved in Mark 9:29.

3. Different viewpoints you’ll see in discussions

If you look at current forum and social media discussions, you’ll see several angles on “why is Matthew 17:21 missing?”

  1. Textual-critical / scholarly view
    • The verse is a later scribal addition; modern Bibles are correcting the text back to what Matthew wrote.
 * Mark 9:29 still teaches “prayer” (and in many manuscripts “prayer and fasting”), so the doctrine isn’t “deleted,” just not duplicated in Matthew.
  1. Traditional / KJV-focused view
    • Some argue that deleting the verse is part of a trend to weaken the Bible or remove emphasis on fasting and spiritual warfare.
 * They trust the later manuscript tradition behind the KJV more than the critical text built from earlier manuscripts.
  1. Devotional / spiritual warfare view
    • Some believers see the missing verse as symbolic: that spiritual forces don’t want Christians to rediscover the power of prayer and fasting.
 * Comments often frame this as “the devil doesn’t want you to know this verse,” using it to promote deeper fasting and prayer.
  1. Practical / pastoral view
    • Pastors and teachers often reassure people:
      • Your Bible isn’t broken or corrupted; the note is there to be transparent.
      • The message (faith, prayer, fasting, spiritual warfare) is still clearly taught elsewhere, especially in Mark 9:29 and other passages on fasting and prayer.

4. What this means for you when you read the passage

If you’re reading Matthew 17 and notice the missing verse:

  • Check the footnote : it usually explains that “Some manuscripts add verse 21…” and may quote it.
  • Read the parallel story in Mark 9:14–29 —there you’ll see explicitly that Jesus says some demons only come out by prayer (and in many manuscripts: “prayer and fasting”).
  • Remember: the heart of the story—Jesus’ authority, the need for faith, and the call to deep dependence on God—is unchanged whether or not your edition prints Matthew 17:21 in the main text.

5. Mini FAQ

Q: Does this mean the Bible is unreliable?
A: The opposite. The fact that editors openly mark doubtful verses, instead of hiding the issue, shows they are trying to present the most accurate reconstruction of the original text.

Q: Is the teaching about prayer and fasting still biblical?
A: Yes. Even if Matthew 17:21 is placed in a footnote, Mark 9:29 carries the same idea, and fasting plus prayer are taught elsewhere in Scripture.

Q: Why keep the verse number at all?
A: For continuity. Chapter and verse numbers were added long after the original writings, so dropping a number entirely can cause confusion in older references and commentaries. Many translations keep the number but skip the text or push it to a note.

Small story-style illustration

Imagine a teacher who gave a powerful line in one lecture—“Some problems only move when you combine effort and humility”—and a student later copied that line into their notes for a different lecture because it “fit so well.” Years later, historians comparing multiple copies of those notes would realize that line originally belonged to lecture A (Mark 9:29), and was imported into lecture B (Matthew 17) by a well-meaning copyist. Their job would not be to erase the line from history, but to put it back where it first belonged and tell future readers exactly what happened. That’s essentially what is happening with Matthew 17:21 in modern Bible editions.

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Why is Matthew 17:21 missing in many modern Bibles? Learn how ancient manuscripts, textual criticism, and current forum discussion all shape this debated verse on prayer and fasting.

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