LUKE 17:5–6
FAITH THAT MOVES THE IMPOSSIBLE
BRIEF INTERPRETATION
Text – Luke 17:5–6
5 And the apostles said to the Lord, “Increase our faith.”
6 The Lord replied, “If you have faith the size of a mustard seed, you would say to this mulberry tree, ‘Be uprooted and planted in the sea,’ and it would obey you.”
Historical and Jewish Context
A mustard seed was one of the smallest seeds known in ancient Palestine, yet it grew into a surprisingly large plant. Jesus used this well-known image to illustrate how even a tiny amount of authentic faith possesses tremendous potential. The mulberry tree (likely the black mulberry) was known for its deep, strong roots and its longevity—an image of something firmly established and difficult to move. Planting a tree in the sea would have been considered impossible, emphasizing the striking power of divine faith. The apostles’ request for increased faith follows Jesus’ teaching on forgiveness, a command that exceeded human strength and prompted their plea.
Catholic Theological Perspective
Faith is a supernatural gift infused by God, enabling believers to assent to divine truth and trust in God’s power. Jesus teaches that the effectiveness of faith lies not in its size but in its authenticity and its connection to God’s omnipotence. The mustard seed symbolizes even the smallest act of trust. Catholic theology emphasizes that faith grows through prayer, sacraments, Scripture, and acts of charity. The image of uprooting a mulberry tree expresses that faith makes possible what human effort cannot achieve—overcoming sin, bitterness, unforgiveness, and obstacles to holiness. True faith aligns the believer with God’s will, allowing divine power to work through human weakness.
Parallels in Scripture
Mt 17:20 – Faith the size of a mustard seed moving mountains.
Mk 9:24 – “I do believe; help my unbelief!” expressing faith seeking increase.
Heb 11:1 – Faith as the assurance of things hoped for.
Jn 15:5 – Apart from Christ, we can do nothing.
Eph 3:20 – God is able to accomplish far more than we ask or imagine.
Key Terms
Faith – Trust in God’s power, fidelity, and truth.
Mustard seed – Symbol of seemingly small yet effective faith.
Mulberry tree – Image of deeply rooted obstacles overcome by grace.
Increase our faith – Prayer for divine help in living the demands of discipleship.
Catholic Liturgical Significance
This passage appears in weekday liturgies and teaching on faith. It guides catechesis on the theological virtue of faith, especially for catechumens and those preparing for Confirmation. It is frequently referenced in retreats and spiritual direction as a reminder that God works powerfully through even the smallest acts of trust.
Conclusion
Jesus teaches that even a small, sincere faith unleashes God’s transforming power. What seems immovable or impossible yields to grace when the believer trusts in God rather than in self.
Reflection
Where do I feel overwhelmed or powerless? Is there a “mulberry tree” in my life that only God can uproot? Jesus invites me to offer even a small seed of faith and trust in His power.
Prayer
Lord Jesus, increase my faith. Strengthen my trust in Your love and power. Help me believe that, with You, all things are possible. Plant true faith in my heart so that Your grace may overcome every obstacle. Amen.
DETAILED INTERPRETATION
INTRODUCTION
Luke 17:5–6 records the disciples’ heartfelt request to Jesus: “Increase our faith.” Their plea arises from the demanding teachings on forgiveness and responsibility that precede it. Recognizing their own limitations, the disciples sense that such radical obedience cannot be sustained by human strength alone. Jesus’ response reframes their understanding of faith, shifting the focus from quantity to authenticity.
Jesus explains that faith, even as small as a mustard seed, possesses transformative power. He uses the striking image of a mulberry tree being uprooted and planted in the sea—an action humanly impossible. The point is not spectacle but trust. True faith, however small, is effective when it is genuine and directed toward God. Faith works not by its size, but by its relationship to God’s power and will.
Lk 17:5 — “And the apostles said to the Lord, ‘Increase our faith.’”
This brief verse reveals a moment of profound humility. After hearing Jesus’ demanding teaching on forgiveness without limits, the apostles recognize their own inadequacy. They do not argue, negotiate, or excuse themselves. Instead, they turn to the only source capable of sustaining such radical obedience—the Lord Himself.
The request “Increase our faith” is not about intellectual belief but about trusting God enough to live what He commands. The apostles understand that forgiveness “seven times a day” exceeds natural human strength. Faith, in biblical understanding, is reliance on God’s power at work within human weakness. Their prayer acknowledges that discipleship is impossible without grace.
Luke deliberately notes that it is the apostles—those chosen for leadership—who make this request. Within the Gospel of Luke, this highlights a key truth: authority in the Church begins with dependence on God. Those who teach and guide others must first admit their need for deeper faith.
Historical and Jewish Context
In Jewish prayer, asking God to “increase” something often implied a desire for inner transformation.
Faith was understood as fidelity and trust, not merely belief in doctrines.
Rabbis taught that obedience to God’s commands required divine assistance.
Catholic Theological Perspective
Faith is a gift from God that can grow through prayer and obedience (cf. CCC 162).
The apostles’ prayer reflects the Church’s constant need for grace to live the Gospel.
True faith expresses itself in action, especially in forgiveness and charity.
Key Terms
Apostles — those sent and entrusted with authority
Increase — growth and strengthening of a divine gift
Faith — trustful surrender to God’s will and power
Conclusion
Lk 17:5 teaches that when the Gospel seems too demanding, the correct response is not resistance but prayer. God never commands without also offering the grace to obey.
Reflection
When God’s call challenges me beyond my strength, do I withdraw—or do I pray for deeper faith?
Prayer
Lord Jesus, increase my faith. Strengthen my trust in You, especially when Your Gospel asks more than I feel able to give. Let my weakness become a place where Your grace is revealed. Amen.
Lk 17:6 — “The Lord replied, ‘If you have faith the size of a mustard seed, you would say to this mulberry tree, “Be uprooted and planted in the sea,” and it would obey you.’”
Jesus answers the apostles’ plea with both encouragement and correction. He does not promise more faith in quantity but points to the power of genuine faith, however small. The issue is not how much faith one has, but whether it is real—alive, trusting, and surrendered to God.
The mustard seed was one of the smallest seeds known in Palestine, commonly used in Jewish teaching to signify something tiny yet potent. By choosing this image, Jesus reassures the apostles that even fragile faith, if authentic, can accomplish what seems impossible. Faith is powerful not because of the believer, but because of the God in whom the believer trusts.
The image of the mulberry tree (or sycamine tree) deepens the teaching. This tree was known for its deep and extensive roots, making it extremely difficult to uproot. Jesus’ imagery suggests obstacles that appear firmly entrenched—habits, sins, resentments, or fears. Within the Gospel of Luke, the context is forgiveness: faith enables disciples to do what human strength cannot, especially forgiving repeatedly.
Historical and Jewish Context
Rabbis often used hyperbolic language to emphasize spiritual truths.
The mustard seed symbolized insignificance that leads to surprising growth.
The mulberry tree was proverbially difficult to uproot due to its deep roots.
Catholic Theological Perspective
Faith, even when small, participates in God’s power (cf. CCC 1814).
What seems impossible to human effort becomes possible through grace.
Faith expresses itself in obedience, especially in demanding commands like forgiveness.
Key Terms
Mustard seed — small but living faith
Mulberry tree — deeply rooted obstacles
Obey you — creation responding to God’s power through faith
Conclusion
Lk 17:6 teaches that the power of faith lies not in its size but in its authenticity. Even the smallest true faith, united with God’s will, can uproot what seems impossible.
Reflection
Do I underestimate what God can do through my small, imperfect faith?
Prayer
Lord Jesus, take my small faith and make it living and strong. Help me trust You enough to obey, even when the task feels impossible. May Your power work through my weakness. Amen.
CONCLUSION
For believers today, Luke 17:5–6 offers deep encouragement. Spiritual growth is often hindered by the belief that one needs extraordinary faith to overcome challenges. Jesus teaches instead that sincere trust, even when fragile, opens the way for God to act. What seems impossible becomes possible when faith rests in God rather than in personal strength.
At the same time, this passage challenges believers to exercise the faith they already have. The call is not to wait for greater faith before acting, but to act faithfully with what has been given. When believers step forward in obedience, forgiveness, and trust, God’s power is revealed through ordinary faith lived consistently.
PRAYER
Lord Jesus, strengthen our faith when we feel weak or inadequate. Teach us to trust You with the faith we have, however small it may seem. Help us to act in obedience and confidence, knowing that all things are possible with You. May our faith be living, humble, and open to Your transforming power. Amen.