Meaning of Matthew 17:20

Jesus uses the inability of his disciples to cast out a demon from a boy as a teaching moment about the nature and power of faith. The disciples had attempted to expel the demon, as they had done before, but were unsuccessful. Their failure, Jesus explains, was not due to a lack of power on his part, nor a deficiency in the spiritual realm's capacity to act, but rather a deficit in their own faith. He emphasizes that even a faith as minuscule as a mustard seed, when possessed, has the inherent potential to accomplish what appears impossible, illustrating that the efficacy of divine intervention is often directly correlated with the quality and quantity of the faith exercised by believers.

Context and Background

This episode occurs in Matthew 17:14-21, immediately following the Transfiguration. A man approaches Jesus, desperate for his son’s healing, recounting how the disciples were unable to cast out a demon. The crowd’s reaction and the disciples’ admitted failure highlight a moment of spiritual weakness among Jesus’ closest followers. Jesus’ subsequent rebuke is not of the disciples' overall commitment, but specifically of their “little faith” (ὀλιγόπιστος - oligopistos), a term he uses elsewhere to address their anxieties and doubts. The demon’s description as “lunatic” (σεληνιάζεται - seleniazetai) suggests a severe affliction, possibly epilepsy, but understood by the people of that time as demonic possession.

Key Themes and Messages

The central themes are the power of faith and the limitations imposed by doubt. Jesus is not promoting a simplistic "name it and claim it" theology, but rather the transformative power that arises from a genuine, albeit small, reliance on God's omnipotence. The mustard seed serves as a powerful metaphor for something incredibly small yet possessing immense potential for growth and impact. The implication is that the object of faith (God) is all-powerful, and the size of the faith is less important than its presence and its focus on the divine. The impossibility of the task (moving a mountain) underscores that genuine faith trusts in God's ability to overcome any obstacle, regardless of human perception.

Spiritual Significance and Application

This verse offers profound encouragement to believers who may feel their faith is insufficient. It teaches that God’s power is not contingent upon the magnitude of our faith, but rather on the object of our faith. Even a nascent, underdeveloped faith, when directed towards God, can unlock divine intervention. The application is to cultivate a posture of dependence on God, trusting in His will and power even when circumstances seem insurmountable. It calls for intentional spiritual discipline to strengthen faith, moving beyond mere intellectual assent to a deep, active trust.

Relation to the Broader Biblical Narrative

The concept of faith as a catalyst for divine action is a recurring motif throughout Scripture. From Abraham’s faith being counted as righteousness (Genesis 15:6) to the numerous healings performed by Jesus and the apostles based on the faith of the afflicted or those bringing them, the Bible consistently links human belief with God’s responsive power. This verse fits within the larger narrative of God’s covenant faithfulness and His desire to empower His people, demonstrating that His kingdom's advance is facilitated by the faith of those who are part of it. It echoes Old Testament promises of God’s capability to perform great works for His people when they trust Him.

Analogies

The mustard seed is a potent analogy. A tiny seed, when planted and nurtured, can grow into a large shrub, providing shade and shelter. Similarly, a small act of trust in God, when nurtured through prayer and obedience, can lead to significant spiritual growth and the accomplishment of seemingly impossible feats. Another analogy might be a small key that, despite its size, can unlock a massive vault. The key itself is insignificant, but its purpose and ability to engage with the lock are what grant access to immense treasure. In this case, faith is the key, and God’s power is the treasure or the secured realm.

Relation to Other Verses

This passage resonates with other teachings on faith, such as:

• Mark 11:22-24: "“Have faith in God,” Jesus answered. “Truly I tell you, if anyone says to this mountain, ‘Go, throw yourself into the sea,’ and does not doubt in their heart but believes that what they say will happen, it will be done for them. Therefore I tell you, whatever you ask for in prayer, believe that you have received it, and it will be yours.”" This parallel passage emphasizes the importance of believing in one's heart and the connection between faith and prayer.
• Hebrews 11:1: "Now faith is confidence in what we hope for and assurance about what we do not see." This definition provides a theological foundation for understanding faith as a confident expectation and a conviction of unseen realities, aligning with Jesus’ teaching about trusting in God’s power.
• 1 Corinthians 13:2: "If I have the gift of prophecy and can fathom all mysteries and all knowledge, and if I have a faith that can move mountains, but do not have love, I am nothing." Here, Paul uses the "move mountains" hyperbole to underscore that even the greatest faith is meaningless without love, contextualizing the purpose of such faith within a framework of divine love and ethical conduct.
• Ephesians 2:8-9: "For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God— not by works, so that no one can boast." This verse highlights that salvation itself is a gift received by faith, reinforcing the idea that faith is the conduit through which God's grace operates, rather than a human achievement.