King James Version

What Does Matthew 17:19 Mean?

Matthew 17:19 in the King James Version says “Then came the disciples to Jesus apart , and said, Why could not we cast him out? — study this verse from Matthew chapter 17 with commentary, cross-references, and original Greek word analysis.

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

Matthew 17:19 · KJV


Context

17

Then Jesus answered and said, O faithless and perverse generation, how long shall I be with you? how long shall I suffer you? bring him hither to me.

18

And Jesus rebuked the devil; and he departed out of him: and the child was cured from that very hour.

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.


Commentary

KJV Study Commentary
Then came the disciples to Jesus apart, and said, Why could not we cast him out? The disciples' private inquiry (κατ' ἰδίαν, kat' idian, "apart, privately") shows appropriate humility—they don't demand explanation publicly but seek understanding in private. Their question "Why could not we?" (διὰ τί ἡμεῖς, dia ti hēmeis) reveals perplexity. They possessed delegated authority (Matthew 10:1) and had previously succeeded (Luke 10:17), so this failure bewildered them.

Jesus's response (v. 20) is stunning: "Because of your unbelief" (δι' ἀπιστίαν, di' apistian). Despite witnessing countless miracles and receiving Christ's empowerment, their faith remained deficient. He explains that even mustard-seed faith suffices to move mountains—the issue wasn't faith's quantity but quality. Authentic faith, however small, connects to God's unlimited power; false confidence, however great, accomplishes nothing.

Mark's parallel adds: "This kind can come forth by nothing, but by prayer and fasting" (Mark 9:29). The disciples relied on past success and positional authority without maintaining vital connection to God through prayer. They treated spiritual authority as personal possession rather than borrowed power requiring constant dependence. This teaches that ministry effectiveness depends not on gifting or position but on abiding relationship with Christ (John 15:5). Apart from Him, we can do nothing.

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Historical & Cultural Context

This question initiated crucial discipleship training. The disciples discovered that spiritual authority isn't automatic or permanent—it requires ongoing cultivation through prayer, fasting, and faith. Jewish background emphasized ritual and technique, but Jesus redirects focus to heart relationship. The phrase "this kind" suggests demonic hierarchy or varying resistance levels, requiring intensified spiritual warfare for stronger opposition.

Church fathers noted this passage as foundational for understanding spiritual warfare. Chrysostom observed that the disciples' failure demonstrated God's wisdom in occasionally allowing His servants to fail, lest they grow proud. Augustine emphasized that faith's efficacy depends on its object (Christ), not subjective strength. The Reformers highlighted the necessity of continual dependence—even apostles failed when relying on themselves. Modern charismatics and cessationists debate applications, but all agree: authentic ministry flows from humble, prayerful dependence on God, not human ability.

Reflection Questions

  1. What is the difference between having positional authority from Christ and maintaining the spiritual vitality to exercise that authority effectively?
  2. How does the requirement for prayer and fasting challenge modern assumptions about instant results and technique-driven ministry?
  3. When have you relied on past spiritual success or positional authority rather than present dependence on God, resulting in failure?

Original Language Analysis

Greek · 15 words
Τότε1 of 15

Then

G5119

the when, i.e., at the time that (of the past or future, also in consecution)

προσελθόντες2 of 15

came

G4334

to approach, i.e., (literally) come near, visit, or (figuratively) worship, assent to

οἱ3 of 15
G3588

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

μαθηταὶ4 of 15

the disciples

G3101

a learner, i.e., pupil

τῷ5 of 15
G3588

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

Ἰησοῦ6 of 15

to Jesus

G2424

jesus (i.e., jehoshua), the name of our lord and two (three) other israelites

κατ'7 of 15

apart

G2596

(prepositionally) down (in place or time), in varied relations (according to the case (genitive, dative or accusative) with which it is joined)

ἰδίαν8 of 15
G2398

pertaining to self, i.e., one's own; by implication, private or separate

εἶπον9 of 15

and said

G2036

to speak or say (by word or writing)

Διατί10 of 15

Why

G1302

through what cause ?, i.e., why?

ἡμεῖς11 of 15

we

G2249

we (only used when emphatic)

οὐκ12 of 15

not

G3756

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

ἠδυνήθημεν13 of 15

could

G1410

to be able or possible

ἐκβαλεῖν14 of 15

cast

G1544

to eject (literally or figuratively)

αὐτό15 of 15

him

G846

the reflexive pronoun self, used (alone or in the comparative g1438) of the third person, and (with the proper personal pronoun) of the other persons


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 17:19 contributes to our understanding of God's character and His relationship with humanity. Consider how this verse connects to the broader themes of Scripture.

Cross-References

Verses related to Matthew 17:19 from Treasury of Scripture Knowledge

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