What are the challenges to your faith? When you pray for something and don’t get the answer you hope for, is the problem that you just don’t have enough faith? In Matthew 17:14–23 (and our focus is verse 20) Jesus not only rebukes his disciples for their lack of faith, but he also assures you of what happens through your faith.
Beware of little faith. The effects of sin are evident in illness and suffering. Jesus, Peter, James and John were descending from the Mount of Transfiguration when they met a crowd. Its focus was on a boy and the unsuccessful efforts of the remaining disciples to help him. The boy may have been an epileptic. The father uses the term moonstruck in line with the medical thinking of the day. The boy suffered from severe physical symptoms. But this was not just the ordinary effect of living in a sin-cursed world. Additionally, in this case, was the presence of a demon who caused this suffering. There is a horrible contrast. The incarnate Son of God had just been transfigured on the mountain. Now, as he comes down, it is as though Satan is saying, “I too can inhabit humans. And instead of glory, look at my destructive power.” Though we today need to be cautious about assuming that demon possession lies behind illness, certainly suffering, illness and death entered the world because of sin and are part of the impact that Satan has had on creation.
Jesus rebukes unbelief. Real anger appears in Jesus’ rebuke. This incident occurs in the context of increasing opposition to Jesus. Included in the crowd were leaders of Israel, arguing with the disciples (see Mark 9:14). The crowd may well have included curiosity seekers, skeptics, and outright opponents of Jesus. The disciples had been unable to cure the boy, and doubtless there were those who were rejoicing in that. Jesus has just come from a glorious experience, from which he, full of faith, is going about the task of obeying the Father, following the road that leads to Jerusalem and his death, verses 22, 23. His rebuke reveals impatience with the hardness of heart revealed in the crowd. Like Moses many centuries before, he came down from the mountain to encounter unbeleif. His rebuke touches not only the immediate hearers, but the whole generation, which was busy either rejecting or ignoring the Messiah. Indeed, Jesus would not long continue to walk on earth. But not only does Jesus reprove the crowd, but the rebuke and casting out of the demon is an exercise of his sovereign authority over even Satan and his hosts.
Jesus challenges your little faith. Although Jesus rebukes the crowd for their lack of faith he challenges the disciples for their little faith. Perhaps the surrounding unbelief of the crowd had affected them. Perhaps the physical absence of the Savior had dimmed their trust. But it appears that Jesus criticizes them for failing to use adequately the faith they had. “The disciples’ faith was no match for the unbelief that surrounded them. Unfortunately, this is often the case with the Church and the believers. Today, too, God’s people are to bear testimony to the Lord Jesus. If they believe in His name, their lives will be freed from sin and from the devil’s control. But they, too, live in a world full of unbelief, which so often paralyzes the power of their faith. Still, it is sin for believers if they cannot withstand unbelief.” (S.G. De Graaf, Promise and Deliverance, Vol. 3, p. 258)
Use your mustard seed faith. By faith nothing is impossible. Mustard seeds are small–the smallest seeds in agricultural use in Palestine, yet they grew into a relatively large plant. Even a little faith, a tiny, beginning faith, can accomplish things that are seemingly impossible. Zechariah preached to a post-exilic remnant, tasked with rebuilding the temple. God assures them that it will be built, not by might or power, but by his Spirit. He warns them not to despise the day of small things. The reference to moving mountains is hyperbolic language. Jesus is not suggesting arbitrary rearrangement of the geography. But things that are humanly speaking impossible can and are accomplished by trust in Christ. Perhaps you have not seen Mt. Hood relocated. But you have seen sinners brought to repentance and new life. You have seen God’s grace touch your own life and change its direction. All this happens as you are united to Christ by faith in him. The size of your faith is not the crucial question. Even a small, beginning faith can grow into something much larger. The important things is whether you do indeed trust in the Lord Jesus Christ.
Trust your Savior! Matthew ties in with this incident of healing another pronouncement by Jesus of his coming suffering, death, and resurrection, verses 22 ,23. Jesus is walking the path of faith in obedience to his Father in heaven. The Father’s voice had commanded that you listen to him. He now speaks of his work, which he was about to fulfill. Focus, not on the mechanics of faith, but on the One in whom you trust. Recognize the value of his substitutionary death. Experience the power of his resurrection. Trust in him as your Savior. Machen focuses on what faith is: “Even very imperfect and very weak faith is sufficient for salvation: salvation does not depend upon the strength of our faith, but it depends upon Christ. When you want assurance of salvation, think not about your faith, but about the Person who is the object of your faith…. Weak faith will not remove mountains, but there is one thing at least that it will do: it will bring a sinner into peace with God. Our salvation does not depend upon the strength of our faith; saving faith is a channel not a force. If you are once really committed to Christ then despite your subsequent doubts and fears you are His for ever.” (J. Gresham Machen, What Is Faith? pages 250–251) As you trust in him, your faith can deal with the temptations, the suffering, the sorrow, the losses—as well as the triumphs and good times that come your way as you walk in obedience to him.
It’s not really a question of how big your faith is. Even if it is as small as a mustard seed, if it trusts in Christ, it’s big enough!