GOING DEEPER: WHY COULDN'T THE DISCIPLES CAST OUT THE SPIRIT?

Mark 9:28–29 — Authority, Prayer, and Dependence on God

TEXT B4 TRADITION — Read First. Conclude Later.

Jesus had given His disciples authority over unclean spirits.

They had successfully cast out demons before (Mark 6:7, 13).

But when a father brought his suffering son to them, they could not help him.

After Jesus delivered the boy, the disciples asked Him privately:

“Why could not we cast him out?” (Mark 9:28, KJV)

Jesus answered:

“This kind can come forth by nothing, but by prayer and fasting.” (Mark 9:29, KJV)

What had gone wrong?

And what does Jesus' answer teach us?

1. They Had Previously Received Authority

Mark 6:7, 13

Jesus had sent His disciples out with authority over unclean spirits.

Mark tells us they cast out many demons.

Their failure in Mark 9 was therefore surprising.

But receiving authority from Jesus did not mean they possessed spiritual power independently of Him.

We should not assume that earlier success guaranteed success in every future situation.

2. What Does “This Kind” Mean?

Mark 9:29

Jesus says, “This kind.”

The most natural reading is that He is referring to the kind of unclean spirit involved in this particular case.

But Mark does not explain what made this spirit different.

He does not give us a list of different classes of demons.

Nor does he describe different procedures for dealing with each class.

We should therefore be careful about building an elaborate teaching about categories of demons from these two words.

Jesus tells us what was necessary in this situation. He does not explain everything we might wish to know about the spirit.

3. Why Did Jesus Mention Prayer?

Mark 9:29

Jesus' answer points to prayer.

Prayer is an expression of dependence upon God.

The disciples had received authority, but they were not the source of that authority.

Their previous success did not make them independent of the One who had sent them.

Mark does not explicitly tell us whether the disciples had neglected prayer, become overconfident, or made some other mistake.

We should not claim to know.

But Jesus' answer makes dependence upon God central to understanding their failure.

Having received authority from God is not the same as possessing power apart from God.

4. What About “And Fasting”?

Mark 9:29

The King James Version reads:

“This kind can come forth by nothing, but by prayer and fasting.”

However, some early Greek manuscripts contain only the words “except by prayer.”

Most modern critical editions of the Greek New Testament follow that shorter reading.

That is why many modern translations omit “and fasting” from the verse or place those words in a footnote.

This does not mean fasting is never appropriate for Christians.

The New Testament discusses fasting elsewhere.

But we should not build a requirement for fasting in this particular situation upon words whose inclusion in Mark 9:29 is textually disputed.

The central point of the verse remains prayer and dependence upon God.

5. What Does This Teach Christians Today?

This passage does not authorize us to assume that Christians today possess the same miraculous authority Jesus gave His apostles.

Nor does it promise that sufficient prayer will always produce a miracle.

Those conclusions would require evidence from other passages.

What we can learn is that God's servants must never confuse past success with independent spiritual power.

We may have knowledge, experience, or abilities.

But none of those makes us independent of God.

And we should not mistake confidence in ourselves for faith in Him.

Conclusion — Whose Power Was It?

The disciples had previously cast out demons.

But this time they failed.

Jesus succeeded where they could not.

When they asked why, He directed their attention to prayer.

The passage does not explain every detail of their failure.

But it reminds us of something important:

The disciples' authority came from Jesus. It did not originate with them.

And neither should our confidence rest in ourselves.

READ FIRST. CONCLUDE LATER.

Continue Exploring Scripture

Mark 9:14–29 — Faith, Unbelief, and Dependence on God
Return to the full account of the suffering boy and Jesus' deliverance.

Mark 9:23–24 — I Believe; Help My Unbelief!
Examine the father's struggling faith and Jesus' response.

The Bible and Logic
Learn why conclusions must not go beyond the evidence Scripture provides.

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