“Prayer and fasting; ” Or, The Cure of Unbelief

“Then the disciples came to Jesus privately and said, “Why could we not cast it out?” So Jesus said to them, “Because of your unbelief; for assuredly, I say to you, if you have faith as a mustard seed, you will say to this mountain, ‘Move from here to there,’ and it will move; and nothing will be impossible for you. However, this kind does not go out except by prayer and fasting.” — Matthew 17:19-21.

When the disciples saw Jesus cast the evil spirit out of the epileptic whom ” they could not cure,” they asked the Master for the cause of their failure. He had given them “power and authority over all devils, and to cure all diseases.” They had often exercised that power and joyfully told how the devils were subject to them. And yet, they had utterly failed while He was on the Mount. That there had been nothing in the will of God or in the nature of the case to render deliverance impossible had been proved; at Christ’s bidding, the evil spirit had gone out. From their expression, “Why could we not?” it is evident that they had wished and sought to do so; they had probably used the Master’s name and called upon the evil spirit to go out. Their efforts had been vain, and, in the presence of the multitude, they had been put to shame. “Why could we not?”

Because of your unbelief

— Jesus

Christ’s answer was direct and plain; “Because of your unbelief.” The cause of His success and their failure was not owing to His having a unique power to which they had no access. No, the reason was not far to seek. He had so often taught them that there is one power, faith, to which everything must bow in the kingdom of darkness, as in the kingdom of God. In the spiritual world, failure has but one cause, the want of faith. Faith is the one condition all Divine power can enter into man and work through him. It is the susceptibility of the unseen; man’s will yielded up to, and molded by, the will of God. The power they had received to cast out devils, they did not hold in themselves as a permanent gift or possession; the power was in Christ, to be received, held, and used by faith alone, living faith in Himself. Had they been full of faith in Him as Lord and Conqueror in the spirit world, had they been full of faith in Him as having given them authority to cast out in His name, this faith would have given them victory. “Because of your unbelief” was, for all time, the Master’s explanation and reproof of impotence and failure in His Church.

But such want of faith must have a cause too. The disciples might have asked: “And why could we not believe?” Our faith has cast out devils before this; why have we failed to believe?” The Master tells them before they ask: “This kind goeth not out but by fasting and prayer.” As faith is the simplest, it is the highest exercise of the spiritual life, where our spirit yields itself in perfect receptivity to God’s Spirit, and so is strengthened to its highest activity. This faith depends entirely upon the state of the spiritual life; only when this is strong and in full health, when the Spirit of God has full sway in our life, is there the power of faith to do its mighty deeds. And therefore Jesus adds, “Howbeit this kind goeth not out but by fasting and prayer.” The faith that can overcome such stubborn resistance as you have seen in this evil spirit, Jesus tells them, is impossible except for men living in very close fellowship with God and in exceptional separation from the world — in prayer and fasting. And so He teaches us two lessons concerning the prayer of profound importance. The one that faith needs a life of prayer to grow and keep strong. The other is that prayer needs fasting for its complete and perfect development.

Faith needs a life of prayer for its full growth. In all the different parts of the spiritual life, there is such close union, such unceasing action, and reaction, that each may be both cause and effect. Thus it is with faith. There can be no true prayer without faith; some measure of faith must precede prayer. And yet prayer is also the way to more faith; there can be no higher degrees of faith except through much prayer. This is the lesson Jesus teaches here.

There is nothing that needs so much to grow as our faith. “Your faith groweth exceedingly,” is said of one Church. When Jesus spoke the words, “According to your faith be it unto you.” He announced the law of the kingdom, which tells us that all have not equal degrees of faith, that the same person has not always had the same degree, and that the measure of faith must always determine the extent of power and blessing. If we want to know where and how our faith is to grow, the Master points us to the throne of God. That faith can increase in prayer, exercise my faith, and fellowship with the living God. Faith can only live by feeding on what is Divine, on God Himself.

In the adoring worship of God, the waiting on Him and for Him, the deep silence of the soul that yields itself for God to reveal Himself, the capacity for knowing and trusting God will be developed. As we take His word from the Blessed Book and bring it to Himself, asking Him to speak it to us with His living, loving voice, the power will come fully to believe and receive the word as God’s own word to us. It is in prayer, in living contact with God, in living faith, that faith, the power to trust God, and in that trust, to accept everything He says and every possibility He has offered to our faith will become strong in us. Many Christians cannot understand what is meant by the much prayer they sometimes hear spoken of; they cannot conceive, nor do they feel the need to spend hours with God. But what the Master Says, the experience of His people has confirmed; men of strong faith are men of much prayer.

This brings us back to the lesson we learned when Jesus, before telling us to believe that we receive what we ask, first said, “Have faith in God.” It is God, the living God, into whom our faith must strike its roots deep and broad; then, it will be strong to remove mountains and cast out devils. “If ye have faith, nothing shall be impossible to you.” Oh! If we do but give ourselves up to the work God has for us in the world, coming into contact with the mountains and the devils there are to be cast away and cast out, we should soon comprehend the need there is of much faith, and of much prayer, as the soil in which alone faith can be cultivated. Christ Jesus is our life, the life of our faith too. It is His life in us that makes us strong and makes us simple to believe. In the dying to self, which much prayer implies, in the closer union to Jesus, the spirit of faith will come in power. Faith needs prayer for its full growth.

And prayer needs fasting for its full growth; this is the second lesson. Prayer is the one hand with which we grasp the invisible; fasting the other, with which we let loose and cast away the visible. In nothing is a man more closely connected with the world of sense than his need for food and his enjoyment of it. It was the fruit, suitable for food, with which man was tempted and fell in Paradise. It was with bread made of stones that Jesus, when hungry, was tempted in the wilderness, and in fasting, He triumphed. The body has been redeemed to be a temple of the Holy Spirit; it is in the body and spirit. It is extraordinary. Scripture says in eating and drinking, we are to glorify God. It is to be feared that there are many Christians to whom this eating, to the glory of God, has not yet become a spiritual reality. And the first thought suggested by Jesus’ words concerning fasting and prayer is that it is only in a life of moderation, temperance, and self-denial that there will be the heart or the strength to pray much.

But then there is also its more literal meaning. Sorrow and anxiety cannot eat; joy celebrates its feasts with eating and drinking. There may come times of intense desire, when it is strongly felt how the body, with its appetites, lawful though they are, still hinder the spirit in its battle with the powers of darkness, and the need is felt of keeping it under. We are creatures of the senses; our mind is helped by what comes to us embodied in concrete form; fasting helps to express, to deepen, and to confirm the resolution that we are ready to sacrifice anything, to sacrifice ourselves, to attain what we seek for the kingdom of God. And He who accepted the fasting and sacrifice of the Son knows to value and accept and reward with spiritual power the soul that is thus ready to give up all for Christ and His kingdom.

And then follows a still broader application. Prayer is reaching out to God and the unseen. Fasting, the letting go of all that is of the seen and temporal. While ordinary Christians imagine that all that is not positively forbidden and sinful is lawful to them and seek to retain as much as possible of this world, with its property, its literature, its enjoyments, the truly consecrated soul is as the soldier who carries only what he needs for the warfare. Laying aside every weight and the easily besetting sin, afraid of entangling himself with the affairs of this life, he seeks to lead a Nazarite life as one specially set apart for the Lord and His service. Without such voluntary separation, even from what is lawful, no one will attain power in prayer; this kind goeth not out but by fasting and prayer.

Disciples of Jesus! Who has asked the Master to teach you to pray? Come now and accept His lessons. He tells you that prayer is the path to a strong faith that can cast out devils. He tells you: “If ye have faith, nothing shall be impossible to you;” let this glorious promise encourage you to pray much. Is the prize not worth the price? Shall we not give up all to follow Jesus in the path He opens to us here; shall we not, if need be, fast? Shall we not do anything that neither the body nor the world around hinders us in our great life work — having interaction with our God in prayer, that we may become men of faith, whom He can use in His work of saving the world.

“Lord, teach us to pray.”

Lord Jesus! How continually Thou hast to reprove us for our unbelief! How strange it must appear to Thee, this terrible incapacity of trusting our Father and His promises. Lord! Let Thy reproof, with its searching, “Because of your unbelief,” sink into the very depths of our hearts and reveal to us how much of the sin and suffering around us is our blame. And then teach us. Blessed Lord, there is a place where faith can be learned and gained — even in the prayer and fasting that brings into living and abiding fellowship with Thyself and the Father.

Savior! Thou Thyself art the Author and the Perfecter of our faith; teach us what it is to let Thee live in us by Thy Holy Spirit. Lord! Our efforts and prayers for grace to believe have been so unavailing. We know why it was; we sought strength in ourselves to be given from Thee. Holy Jesus! Do at length teach us the mystery of Thy life in us, and how Thou, by Thy Spirit, dost undertake to live in us the life of faith, to see to it that our faith shall not fail let us see that our faith will just be a part of that wonderful prayer-life which Thou givest in them who expect their training for the ministry of intercession, not in word and thought only, but in the Holy Unction Thou givest, the inflowing of the Spirit of Thine own life. And teach us how, in fasting and prayer, we may grow up to the faith to which nothing shall be impossible. Amen.


When Blumhardt was passing through his terrible conflict with the evil spirits in those who were possessed and seeking to cast them out by prayer, he often wondered what hindered the answer. One day a friend, to whom he had spoken of his trouble, directed his attention to our Lord’s words about fasting. Blumhardt resolved to give himself to fasting, sometimes for over thirty hours. From reflection and experience, he was convinced that it is more important than is generally thought. He says, “Since the fasting is before God, a practical proof that the thing we ask is to us a matter of true and pressing interest, and since in a high degree it strengthens the intensity and power of the prayer, and becomes the unceasing practice expression of prayer without words, I could believe that it would not be without efficacy, especially as the Master’s words had reference to a case like the present. I tried it without telling anyone, and in truth, the later conflict was extraordinarily lightened by it. I could speak with much greater restfulness and decision. I did not require to be so long present with the sick one, and I felt I could influence without being present.”

Original by Andrew Murray

Revised and Updated by Nathan Zipfel
April 2023


  • Nathan Zipfel

    Ordained Elder in the Church of the Nazarene Pastor of the New Life Church of the Nazarene in Boswell, PA. Batchelor of Arts Pastoral Leadership, Nazarene Bible College Master of Arts, Ministry, Ohio Christian University Master of Social Work, Indiana Wesleyan University Behavioral Health Therapist, Certified Trauma Professional

By Nathan Zipfel

Ordained Elder in the Church of the Nazarene Pastor of the New Life Church of the Nazarene in Boswell, PA. Batchelor of Arts Pastoral Leadership, Nazarene Bible College Master of Arts, Ministry, Ohio Christian University Master of Social Work, Indiana Wesleyan University Behavioral Health Therapist, Certified Trauma Professional

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