Mark 9:29
What does Mark 9:29 mean?
He said to them, “This kind can come out by nothing, except by prayer and fasting.”
The short answer
Mark 9:29 comes at the end of a hard scene. Jesus has just healed a boy whom his own disciples could not help, and afterward, in private, they ask him why they failed. His answer is striking: "This kind can come out by nothing, except by prayer and fasting." Notice what he does not say. He does not correct their method, hand them a better formula, or teach them a new technique. He points instead to a way of life they had neglected.
The disciples had cast out spirits before (Mark 6:13), so it would have been easy for them to treat that power as a skill they possessed—something they could deploy on demand. Jesus' answer exposes the mistake. The power was never theirs. It flows from ongoing dependence on God, and prayer is how that dependence is kept alive. Their failure was not a lack of ability but a kind of prayerlessness: they had tried to do God's work without leaning on God.
One honest note for careful readers: the words "and fasting" do not appear in every ancient copy of Mark, which is why some Bibles print simply "except by prayer." But the pairing is not a stray addition to the tradition. As the scholar J. Thompson observes, Jesus himself joined prayer and fasting when he faced temptation in the wilderness, and the early church did the same at decisive moments—commissioning missionaries and appointing leaders in Acts 13 and 14. Whether or not "and fasting" stood in Mark's original text, the two practices belong together in the life Jesus modeled. Fasting is not a way to impress God; it is a way of clearing space, of admitting hunger for something we cannot supply ourselves. The verse's point holds either way: some things are simply beyond us, and only a life open to God can meet them.
What scholars say
Thompson answers the question of why prayer and fasting appear together here at all: he traces the pairing back to Jesus' own testing in the desert and forward to the early church's discernment in Acts 13–14, while noting that the phrase in Mark 9 rests on some ancient manuscripts.
“Jesus combined prayer and fasting to overcome his temptations in the desert. The early church followed this practice at critical points in its life to discern how God was leading them and to empower their ministry (Acts 13; 14). Some ancient manuscripts indicate that Jesus’ cure of an epileptic boy (Mark 9:14–29) was possible only “by prayer and fasting.” These examples suggest that the combination of prayer and fasting invites a greater measure of God’s power to be released through us than might be possible through prayer alone.”
What it means for you
The most practical thing about Mark 9:29 may be its diagnosis. When we fail at something that matters—parenting, forgiving, serving, enduring—our instinct is to look for a better technique. Jesus redirects the question: not "what did you do wrong?" but "where is your dependence?" Prayer and fasting are not levers that force God's hand; they are ways of living honestly as people who cannot generate their own power.
A small step: the next time you face a situation that feels beyond you, resist the urge to try harder first. Pray first. Consider setting something aside—a meal, a habit, a distraction—as a way of saying, with your body and not just your words, that you need help you cannot manufacture.
Mark 9 in context
Mark 9 opens on a mountaintop, where Peter, James, and John see Jesus transfigured in glory. The descent is jarring: at the bottom of the mountain, a crowd is arguing, a father is desperate, and the remaining disciples have failed to free his son from a destructive spirit. The father's raw prayer—"I believe. Help my unbelief!"—sits at the heart of the scene. Jesus heals the boy, and verse 29 is his private explanation to the disciples afterward. The rest of the chapter continues the theme of misplaced confidence, as Jesus teaches about his coming death and the disciples argue over who is greatest.