Through the Bible
Prayer and Power
In Mark 9:29, Jesus responds to His disciples' failure to cast out a demon by saying, "This kind cannot come out by anything except by prayer". If we had only this verse as our guide, what conclusions would we reach about the nature of demons, the conditions for overcoming them, and the role of prayer in spiritual conflict?
This passage is unique because it highlights the limits of the disciples' power. Earlier, they had successfully driven out demons (Mark 6:13). Yet here, they failed–and Jesus traced that failure not to lack of authority or technique, but to lack of prayer.
This article builds on our earlier study "Evil Spirits: Then and Now" by focusing more closely on the requirements Jesus emphasized, the shift from the apostolic era to the church age, and the safeguards believers must use today when dealing with spiritual evil.
Requirements for Dealing with Demons
| Requirement | Then (Biblical Era) | Now (Church Age) | Scripture References |
|---|---|---|---|
| Delegated Authority | Given directly by Jesus to Apostles and certain disciples. | No apostolic commissions today; authority rests in Christ's name proclaimed in the gospel. | Mark 3:14–15; Acts 19:13–16 |
| Faith in God | Essential for success; lack of faith hindered deliverance. | Faith remains key for resisting Satan's schemes. | Mark 9:23–24; Eph. 6:16 |
| Prayer | Required for certain demons; dependence on God was decisive. | Continual prayer is central to resisting evil. | Mark 9:29; Eph. 6:18 |
| Fasting | Sometimes practiced with prayer in spiritual crises. | Optional, but still useful for seeking God's help. | Acts 13:2–3 |
| Knowledge of Jesus | Demons recognized Him; authority required true relationship. | True discipleship, not formulaic words, gives power. | Mark 1:24; Acts 19:15 |
| Obedience & Holiness | Hypocrisy nullified spiritual power. | Sin gives Satan a foothold. | Matt. 7:21–23; Eph. 4:27 |
| Gospel Proclamation | Deliverance confirmed kingdom preaching. | The gospel itself frees from Satan's power. | Mark 1:39; Col. 1:13 |
| Resistance vs. Engagement | Apostles confronted demons directly. | Believers are called to resist, not to chase after demons. | Matt. 10:1; James 4:7 |
| Reliance on the Spirit | Spirit empowered signs and wonders. | Spirit empowers discernment and endurance. | Acts 10:38; Gal. 5:16 |
Several key encounters in Scripture shape our understanding of this topic: Jesus' authority over demons in Mark 1:21-28, the Legion account in Mark 5:1-20, the disciples' failure in Mark 9:14-29, and the disastrous attempt by the sons of Sceva in Acts 19:13-16. Each example reinforces that success in spiritual conflict depends on God's authority, not human effort.
The New Testament later shifts its emphasis. In Jesus' ministry, exorcisms revealed the kingdom's arrival and validated His authority as Messiah (Luke 11:20). In the Apostolic era, signs confirmed the gospel message (Hebrews 2:3-4). But the epistles emphasize resisting Satan and standing firm in Christ (Ephesians 6:10-18; James 4:7). Thus, the focus moves from spectacular confrontations to living faithfully in Christ's victory.
Today, believers must avoid extra-biblical demonology, guard against sensationalism, and rely on the gospel as the true power of deliverance. Prayer, Scripture, holiness, fellowship, and the Holy Spirit remain the believer's safeguards. Mark 9:29 reminds us that prayer is not an accessory–it is the lifeline for spiritual strength and victory.
- Why do you think the disciples were unable to cast out the demon in Mark 9:29, despite earlier success?
- How does the shift from direct exorcism in the Gospels to resistance in the epistles shape our ministry focus today?
- What practical steps can believers take to rely more on prayer and less on self in spiritual struggles?
- New American Standard Bible 1995
- ChatGPT (OpenAI), Chat on Mark 9:29 – September 2025
- Clinton E. Arnold, "3 Crucial Questions About Spiritual Warfare" (Baker, 1997)
- Merrill C. Tenney, "New Testament Survey" (Eerdmans, 1985)
- F.F. Bruce, "The Book of Acts" (NICNT, 1988)