King James Version

What Does Matthew 17:21 Mean?

Matthew 17:21 in the King James Version says “Howbeit this kind goeth not out but by prayer and fasting. — study this verse from Matthew chapter 17 with commentary, cross-references, and original Greek word analysis.

Howbeit this kind goeth not out but by prayer and fasting.

Matthew 17:21 · KJV


Context

19

Then came the disciples to Jesus apart , and said, Why could not we cast him out?

20

And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.

21

Howbeit this kind goeth not out but by prayer and fasting.

22

And while they abode in Galilee, Jesus said unto them, The Son of man shall be betrayed into the hands of men:

23

And they shall kill him, and the third day he shall be raised again. And they were exceeding sorry.


Commentary

KJV Study Commentary
Jesus explains the disciples' failure to cast out the demon: 'this kind goeth not out but by prayer and fasting.' Some spiritual battles require extraordinary dependence on God. While many manuscripts omit 'and fasting,' the principle remains: certain ministries demand concentrated devotion and self-denial. Reformed practice recognizes prayer and fasting as means of grace, not earning God's favor but expressing desperate dependence. The disciples' failure despite previous successes (Matthew 10:8) shows that past victories don't guarantee present power—continuous reliance on God is essential.

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Historical & Cultural Context

First-century Judaism practiced fasting for spiritual purposes, particularly in connection with prayer for divine intervention. Jesus fasted forty days before beginning ministry (Matthew 4:2). The early church continued this practice (Acts 13:2-3, 14:23). This teaching came shortly before Jesus' Passion, preparing disciples for coming trials requiring intense prayer.

Reflection Questions

  1. What spiritual battles in your life require intensified prayer and fasting?
  2. How does fasting demonstrate dependence on God versus earning His favor?
  3. When have past spiritual victories led to presumption rather than continued dependence?

Original Language Analysis

Greek · 12 words
τοῦτο1 of 12

this

G5124

that thing

δὲ2 of 12

Howbeit

G1161

but, and, etc

τὸ3 of 12
G3588

the (sometimes to be supplied, at others omitted, in english idiom)

γένος4 of 12

kind

G1085

"kin" (abstract or concrete, literal or figurative, individual or collective)

οὐκ5 of 12

not

G3756

the absolute negative (compare g3361) adverb; no or not

ἐκπορεύεται6 of 12

goeth

G1607

to depart, be discharged, proceed, project

εἰ7 of 12
G1487

if, whether, that, etc

μὴ8 of 12
G3361

(adverb) not, (conjunction) lest; also (as an interrogative implying a negative answer (whereas g3756 expects an affirmative one)) whether

ἐν9 of 12

by

G1722

"in," at, (up-)on, by, etc

προσευχῇ10 of 12

prayer

G4335

prayer (worship); by implication, an oratory (chapel)

καὶ11 of 12

and

G2532

and, also, even, so then, too, etc.; often used in connection (or composition) with other particles or small words

νηστείᾳ12 of 12

fasting

G3521

abstinence (from lack of food, or voluntary and religious); specially, the fast of the day of atonement


Study Guide

Historical Context

This verse is found in the book of Matthew. Understanding the historical and cultural background helps illuminate its meaning for the original audience and for us today.

Theological Significance

Matthew 17:21 contributes to our understanding of God's character and His relationship with humanity. Consider how this verse connects to the broader themes of Scripture.

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