When You Fast


Sermon by David Strain on October 31, 2021 Matthew 6:16-18

One of the great recoveries of the Protestant Reformation, especially of the reformed branch of the Reformation under Ulrich Zwingly and Zurich and John Calvin in Geneva, one of the great recoveries was the restoration of what was called, “lectio continua preaching,” that is, preaching verse by verse, systematically through the Scriptures, which is the mainstay of our pulpit ministry here at First Presbyterian Church. And so it is fitting, as we continue in our exposition of the teaching of Jesus on the subject of prayer, that we would be at the next portion of the text in Matthew chapter 6. So do take your Bibles in hand please and turn with me there to Matthew chapter 6. If you have a pew Bible, you’ll find that on page 811.

You may remember that in verses 5 through 8, the Lord Jesus gave general instructions on the proper motives for and the correct manner of prayer. And then in verses 9 through 15, He gave us what we call the Lord’s Prayer, which is, as we’ve seen in some detail over the last several weeks, supplies the content of prayer. So Jesus addresses the “why” and the “how” and even the “what” – the content of faithful prayer here in the center of the Sermon on the Mount. And now having seen all of that, and before we move on from Matthew chapter 6, I wanted to take notice of one last thing related to the subject of prayer. You can see it if you look at verses 16 through 18, which deal with the subject of fasting.

Now it seems to me, one of the kind providences of the Lord that I should have planned to be dealing with this subject this morning, because over the course of the last week or two, several of you have reached out to me to ask about fasting. Many of our small groups on Wednesday nights are reading a book on prayer, which has a brief section in it on the subject of fasting that has raised questions for you. In my judgment, actually, fasting is probably the least understood and the least practiced spiritual discipline of the Christian life today. And so we need to get our heads around this part of Jesus’ teaching.

You may remember a few months ago we called a church-wide day of prayer and fasting. COVID numbers were spiking dramatically in our community. The Taliban had overrun the Afghan government and the church there was facing the threat of terrible persecution. There had been a massive earthquake in Haiti and people were suffering unspeakable deprivation. Our sense was that we were never more desperately in need of true revival here and around the world. And so we fasted and we prayed. Many of you participated and we gathered that night for a prayer service to conclude our fast. It was, in my judgment, a remarkable occasion filled with a sense of the presence and the blessing of God. And yet even after having fasted together like that, many of you who joined in that fast still had lots of questions about what we were doing and what it means and why it matters.

I would hazard a guess that most Christians in our tradition have never fasted for spiritual purposes, do not have a good understanding of the meaning and purpose of fasting, and are unsure about how to go about it as a normal part of their regular Christian piety and walk with God. It is interesting to notice in our passage that Jesus begins His discussion in Matthew chapter 6 of the subject of fasting with the same formula with which He introduced His treatment of the subject of giving alms to the poor in the first part of the chapter, or the subject of prayer. So in verse 2 He said, “When you give to the needy,” and then He gave instruction. In verse 5, he said, “When you pray,” and gave instruction. And now here in verse 16 He says, “And when you fast.” Even though fasting is more than a little foreign to many of us, for the Lord Jesus and for His disciples, fasting was a given. He assumes it here, doesn’t He, right along with charity and prayer, as some of the most basic, routine, ordinary habits of those who follow Him. He does not say, “If you give,” or, “If you pray.” He says, “When you give,” and, “When you pray.” And now He says, “When you fast.” So the operating assumption of the Bible is that, health and circumstances permitting, you will fast if you are a Christian. If you are a Christian, our question tends to be, “Why should I fast?” but the question of the New Testament that is asked of every believer really is, “Why don’t you fast?” So clearly we have some work to do if our life and our piety, if your life and piety is to reflect the teaching of God’s Word in this area.

And so this morning I want to consider the teaching of the Scriptures under these three headings. First of all, we’ll venture a definition of fasting. What is it? What are we talking about? And then we’ll look more closely at verses 16 through 18 of Matthew chapter 6 and notice in verse 16 first of all, the danger of fasting. So the definition, then the danger – how not to do it. And then finally verses 17 and 18, we’ll look at the duty of fasting. The definition, the danger, and the duty of fasting. All of that by way of preface. Let’s pause now and pray and ask for the help of God and then we’ll consider His holy Word. Let us pray.

O Holy Spirit, Lord and giver of life, how we pray for illumination, for Your light, to give light to our understanding, to shine most especially on the face of the Lord Jesus Christ and lead us with renewed yearning and longing and trust and confidence to Him. For we ask this in His name, amen.

Matthew chapter 6 at the sixteenth verse. This is the Word of God:

“And when you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. But when you fast, anoint your head and wash your face, that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.”

Amen.

The Definition of Fasting

Let’s think first of all then about the definition of fasting. And in the interest of clarity, I think it might help to begin with a working definition and then we’ll go back and flesh it out, phrase by phrase, in light of the Scriptures. Okay, so here’s our working definition of fasting. Are you ready for it? Fasting is a voluntary abstention from food and sometimes also from drink, by an individual or a group, accompanied by prayer, for a definition season, for spiritual purposes. That’s what fasting is. That’s my working definition. Let me say it again. Fasting is the voluntary abstention from food and sometimes also from drink, by an individual or group, accompanied by prayer, for a definite season, for spiritual purposes. Let’s unpack that a little bit, clause by clause, from the Scriptures.

First, we said that fasting involves abstention from food and sometimes also from drink. For example, Esther chapter 4 verse 16, the Jews fast and then the passage defines what they were doing and says they refrained “from food and water.” So fasting.

Secondly, we said fasting can be by an individual and by a group. That is, it can be both private and individual as well as public and corporate. So Jesus fasted alone, didn’t He, for forty days in the wilderness. Matthew chapter 4 verse 2, Anna, the prophetess who was waiting for the coming of the Messiah in the temple, every day she, we are told, “fasted day and night” on her own, Luke chapter 2 verse 37. When Paul was converted in Damascus, he was struck blind and for three days he prayed and Luke says he “neither ate nor drank,” Acts chapter 9 verse 9. So fasting is often private and individual.

But sometimes it’s also public and corporate, something we do together. So the fast that we mentioned in Esther 4:16 is an example, where Esther and Mordecai call all the Jews in Susa and around the empire to fast together. In the New Testament, in Acts 13 verses 1 through 3, all the leaders of the church in the city of Antioch fasted together and prayed and then they ordained and sent out Barnabas and Saul as church planters and missionaries. So we said fasting is the voluntary abstention from food and sometimes also from drink, by an individual or a group.

Thirdly we said it is accompanied by prayer. Fasting is typically mentioned in the Bible alongside prayer. It is an adjunct of prayer. Daniel 9:3 has the prophet, Daniel, seeking God by prayer and pleas for mercy with fasting. When the elders sent Barnabas and Saul out as missionaries, they did so, Acts 13:3, “after fasting and praying.” And in Acts 14:23, Paul and Barnabas ordain elders in every church “with prayer and fasting.” And then let’s not overlook our text here in Matthew chapter 6 where, after giving an extended treatment of the motivation and the content of prayer, Jesus does not move on before He appends to that subject and that discussion a treatment of fasting. Fasting and prayer go together.

So fasting is a voluntary abstention from food, sometimes also from drink, by an individual or a group, accompanied by prayer. Fourthly we added that it is for a definite season. The Day of Atonement in Leviticus 16:29 prescribed a fast for that day for all of the ancient people of God, the Jews. The fast that was mentioned in Esther 4:16 was for three days. Jesus fasted for forty days. In Judges 20:26, the people fast only for part of a day. The length seems to reflect the urgency of the need or the concerns of the situation, but there does not seem to appear any absolute rule that dictates how long we must fast for.

Alright, so fasting is the voluntary abstention from food and sometimes also from drink, by an individual or a group, accompanied by prayer for a definite season, and finally we added it is for spiritual purposes. That is to say, it’s not a Biblical fast if you do it, for example, only for health reasons. The objective of the fast is spiritual. It is seeking the will of God to be done in a given circumstance. In his commentary on this part of Matthew’s gospel, Knox Chamblin summarizes the Biblical evidence and gives three reasons for fasting in Scripture. “First,” he says, “people fast to plead with God to act in the face of human need or weakness, impotence. Secondly, “people fast to mourn before God in the face of sin or loss. And thirdly, people fast to wait upon God to reveal Himself and fulfill His purposes.” So we fast in the Scriptures – they fasted to plead with God, to mourn before God, and to wait upon God.

You may remember I tried to sum up the Scriptural purposes of fasting in my introductory remarks to the prayer service we held at the end of that day of congregational fasting and prayer a few months ago and here’s what I said on that occasion. I said, “Fasting serves prayer in much the same way that bold, italics, and underline serve emphasis in a written document. We are kicking up the urgency a notch when we fast. We are saying, ‘Lord, not having Your blessing, Your mercy, Your intervention in this area is like starvation to me.’ And we are saying, ‘Having Your blessing, Your mercy, Your gracious intervention is more necessary, more essential to me than food for my body, than daily bread.’” That is what fasting is.

You know, one of the novelties for me of moving to the American South from the United Kingdom has been the weather. When we first came to Mississippi I still wore glasses, and every day for months, every time I stepped out of the house or out of the car, my lenses, you know, would fog up in the humidity and I would be walking down the street with a big, goofy grin on my face; people looking at me oddly. Because to me, it was just so bizarre – that you would step out of the house and it would be hotter and more humid inside than it is inside! And then there was our first storm. We don’t have storms anything like you have here in the UK – massive, awe-inspiring, you know, window-rattling thunderclaps and lightning that illuminates the landscape in the middle of the night. And then our first ever tornado siren. That was a scary experience. We were up for hours, glued to the local weather station tracking the rotation, waiting to see if we had to get to our safe space and drag the kids from their beds in the middle of the night.

Prayer is like the regular weather report. Fasting is the tornado siren. It is urgent. It is pressing. We feel it deeply. Something in the need of the community drives us beyond the regular course of prayer to fast and to pray. Sometimes it’s a need in the church. Sometimes the need is private and personal and closer to home. Maybe you’re grieving over besetting sin or you’re seeking comfort amidst calamity. Sometimes we want the Lord to visit the ministry of the Gospel with new blessing and power in a season where, in the church’s life, many people are backsliding and drifting away. Whatever the reason, fasting turns on the klaxing that puts your prayers into the loudspeaker, as it were. Andrew Murray, the 19th century South African evangelist says that “Prayer and fasting are like two hands. Whenever we pray it is as though we were reaching out and putting one hand on the mercy seat” – the place that symbolized God’s forgiving presence in the ark of the covenant in the temple in the Old Testament – “one hand on the mercy seat.” “And when we fast,” he says, “we take our other hand off the legitimate things of this world like the comforts of food, and we cast all earthly support aside in order to put both hands on that mercy seat.”

The definition of fasting. Have you got it? Fasting is the voluntary abstention from food and sometimes from drink, by an individual or a group, accompanied by prayer, for a definite season, for spiritual purposes. It is bold, italics, and underline for the language of prayer. It is the tornado siren that shakes heaven. It is both hands on the mercy seat. The definition of fasting.

The Danger of Fasting

Now in the second place, let’s look at Matthew 6:16 and notice the danger of fasting. The law of Moses only required fasting on the Day of Atonement in Leviticus 16:29. Once a year there was a national, mandatory fast. Then later on in Israel’s history, during their exile, there were other national fasts that were begun as the people began to mourn over what they had lost before God and longed for His mercy to be restored. By the time of Jesus, the Pharisees had taken it even further. They fasted twice a week, probably on Mondays and Thursdays. And the problem Jesus is addressing here in Matthew 6 is not that they fasted this frequently; it was how they fasted and why they fasted. It wasn’t the regularity of the fast, but how they fasted and why they fasted.

Look at verse 16. “When you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly I say to you, they have received their reward.” Notice Jesus calls them hypocrites. What exactly is their hypocrisy? Sometimes, as happened for example in Nehemiah chapter 9 verse 1, people mourn and they put on sackcloth, they rub earth through their hair, they weep and they pray and they fast. It’s a very public display and there’s absolutely nothing sinful or hypocritical about it. And at least outwardly, that’s what the people Jesus is speaking about here were doing too. Isn’t it? Jesus says, “When they fast they look gloomy and they disfigure their faces.” The word doesn’t mean they mutilated themselves; it simply means they cover their faces with miserable looks.

And how is that hypocrisy? Isn’t it, in fact, entirely appropriate for someone overcome with grief for their sin to look miserable and to grieve and to let it show? Isn’t this exactly what you would expect? And it’s not just in the ancient Near East that you see that phenomenon. In the history of the church, especially during seasons of revival and spiritual awakening as the Word of Christ is proclaimed, people are sometimes so overcome with the awful realization of their guilt and their sin in the sight of God they cannot hide their sorrow from anyone even if they tried. And their faces are in fact gloomy and disfigured by grief and they cry out and sometimes they are overcome. And quite rightly so.

And so how is what these people are doing here hypocrisy? How is this hypocrisy? Surely this is appropriate, an appropriate expression of grief in the sight of God. Well the key, of course, is their motivation. Do you see how Jesus speaks to their motivation in verse 16? Why do they have gloomy faces as they fast? Why do they make such a show of it all? Or to put the question a little differently, for whose eyes are they fasting? They do it, Jesus says, “that their fasting may be seen by others.” They want to be seen, engaged in heroic self-denial, so that other people might admire them for their piety.

And before we shake our heads at these foolish old Pharisees, let’s take a beat for a moment to acknowledge how quickly this very same instinct rears its ugly heads in our own hearts all too often. The praise of our peers is catnip for the human heart. Isn’t it? We want the credit for our piety. Don’t we? We want to find subtle ways to let folks know what a sacrificial thing we just did, how prayerful we’ve been, how much we gave, how diligent we are, how many hours we have invested in the service of others. And so we do the, “Awe, shucks,” humble brag and we pretend to deflect praises while our hearts are singing out, “Yes! Give me more! That’s what I want!”

And so look, here’s the principle that I think we are being taught. It’s so important to get this right, the principle. The most costly acts of Christian devotion are the most dangerous to our souls if we misuse them. The most costly acts of Christian devotion are the most dangerous to our souls if we misuse them. A soldier’s weapon is a vital instrument in his own defense, but it can be deadly to ourselves if we mishandle it. Prayer and fasting is a loaded gun. It can slay the devil or it can shoot us in the foot. The most costly acts of Christian devotion are the most dangerous to our souls if we misuse them. So let’s ask ourselves, shall we, “How am I using my piety, my devotion? For whose eyes am I really here today? Have I shown up? Am I singing, giving, serving, praying, teaching to be seen by others?” That’s the height of hypocrisy. What an offense to God to engage in acts of sacred devotion like prayer and fasting, not for God’s sake at all, not for God’s glory, not for the advancement of God’s purposes, but secretly you’re using it to deflect praises away from God towards ourselves. That’s what the hypocrites were doing here in Matthew 6:16. Is it what you’ve been doing, I wonder? God isn’t interested in a show, is He? He’s interested in your heart. He’s interested in your heart.

The Duty of Fasting

And that brings us to the last thing to see here. The definition of fasting, the danger of fasting, finally the duty of fasting. Look at 17 and 18 please. “But when you fast, anoint your head and wash your face that your fasting may not be seen by others, but by your Father who is in secret. And your Father who sees in secret will reward you.” As I said earlier, do notice Jesus doesn’t command us to fast here; He simply assumes that we will. “When you fast,” He says, not, “If.” In Matthew 9:15, a little later in the gospel, Jesus is asked the question by the disciples of John the Baptist, they were always fasting, so were the disciples of the Pharisees, but the disciples of Jesus apparently never seemed to fast. How come? That was their question. “Why don’t Your disciples fast?” And Jesus answered them like this. He said, “Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from them and then they will fast.” In other words, fasting doesn’t make much sense in the joy of Jesus’ immediate presence there among His disciples. But the day would soon come when He would be taken from them. These are the days in which we are now living. “Days of mourning,” Jesus calls them; longing for the return of the bridegroom. “In these days,” He says, “it is fitting for us to fast.” It’s not so much a command, is it, as it is an assumption about the most suitable pattern for the Christian life while we wait for the coming of the Lord Jesus Christ. “When you fast” – this is what is fitting while the bridegroom is absent. That’s Jesus’ teaching.

But notice carefully in Matthew 6 how we are to go about it. Negatively, we are not to put in a public display of piety, and positively we are to dress and groom ourselves and go about our business as usual, as normal, so that no one will know whether we are fasting or not. And the point is not to keep it secret, as if, should anyone ever find out, then your fast is invalidated. That’s not the point. Remember, sometimes fasting can be corporate and public, as well as private and individual. That’s not Jesus’ concern. His concern, rather, is that we take every appropriate precaution against our own deceitful hearts. It’s not other people knowing that’s the problem. It’s your own wicked heart that’s the problem because our hearts are always looking for ways to make people admire us. Make sure you fast, verses 16 through 18. Make sure you pray, verses 5 through 8. Make sure you give to the poor, verses 1 through 4 – in such a way, insofar as it depends upon you, other people don’t give their praises to you instead of to God. That’s the burden of Jesus’ teaching. Make sure you fast and pray and give in such a way that your heart does not congratulate itself on how pious it is being.

Interestingly, some scholars suggest that the description of how we are to go about fasting – anointing our head with oil, grooming ourselves well and carefully – actually is intended to communicate preparations not for a fast at all but in fact for a feast, for a banquet, for a celebration. Act as if you were getting ready for a party. That’s what Jesus is saying according to some scholars. I think it’s an important perspective to hold in tension with the teaching of Matthew 9:15 where fasting was a sign of mourning, of longing unfulfilled in the absence of the bridegroom, the Lord Jesus Christ. These two apparently contradictory notes both sound in Christian fasting. At the very same time, we mourn because sin remains in our redeemed hearts, doesn’t it? We mourn because the world to come is not yet here. Jesus has not yet returned. Death and suffering and sickness remain daily terrible realities. We mourn because things are not yet the way they are supposed to be. And so we fast.

And yet, Jesus says we are still to dress for a feast, for a party, for a celebration. We are not to put on a gloomy display. Instead, we are to rejoice at the very same time because we know that Jesus has already come. He has, in fact, endured the cross and paid for our sin in full; death is defeated, the tomb is empty, sin’s mastery is overthrown. Jesus reigns already at the right hand of the Father in glory. Sinners today and every day since Jesus rose from the tomb have passed from death to life under the sound of the Gospel. The Holy Spirit, the third person of the blessed Trinity, dwells in our hearts by faith and the Church, though weak, often compromised, is unstoppable because God has willed that a people from every tribe and language and nation will come and bend their knees to Jesus Christ before He returns.

And so we abstain from food in our fasting, yes because we mourn what remains of the way things ought not to be, and we long for what is not yet. But we also abstain from food in fasting because we are already guests at a richer, sweeter, better banquet than any feast the world can provide. We are invited to the wedding supper of the Lamb at the end of the age. And in the meantime, the Lord Jesus by His Word and Spirit nourishes us and keeps us. In John chapter 6, Jesus says, “My body is true food and My blood is true drink.” That is to say, “I will sustain you. I will nourish your faith. I will keep you and satisfy you.” Jesus spreads a banqueting table in the Gospel of His grace for every believer. We fast from earthly food so as not to spoil our appetite for spiritual food.

And that, I think, is what Jesus means when He says at the end of verse 17, “Your Father who sees in secret will reward you.” What’s the reward for mourning and rejoicing in the fast that is a Gospel feast? What’s the reward? Remember Jesus’ promise? “Blessed are those who hunger and thirst for righteousness, for they shall be filled.” He gives Himself for the satisfaction of your heart. Filled, satisfied, replete with true food and true drink in Jesus Christ Himself.

So the definition of fasting. It is bold, italics, and underlined to the language of prayer. It is the klaxon sounding that shakes the courts of heaven. It is two hands on the mercy seat to receive forgiveness. The danger of fasting. Jesus wants us to watch our own deceitful hearts because the most sacrificial and costly Christian disciplines are the most dangerous to our souls if we misuse them. Fasting is a loaded gun. It can slay the devil or it can shoot us in the foot. And then the duty of fasting. When you fast, not if. Do you fast? Jesus expects you to fast, health and circumstance permitting. But when you fast, He wants you to enter into the tension between the now and the not yet of His kingdom, the joy and the mourning of victory already won but not complete, of Satan already defeated and not yet destroyed, of sin already overthrown and not yet eradicated, of sinners being saved yet many still who have never heard. Gospel fasting is both a feast of joy and a table of mourning. And so let me leave you by turning Jesus’ language in the beginning of verse 16 into a question. “When do you fast? When do you fast?” And if you do, “For whose eyes are you doing it?” Jesus invites you to a Gospel banquet, and true fasting is one tool by which to enjoy the feast.  

Let’s pray together.

Lord Jesus, forgive us for glutting the sole appetite of our hearts with the white bread of worldliness and entertainment and pleasures. And we have such a small and slight appetite for You and for the things of Your Word. Would You begin to teach us and train us in these basic disciplines of the Christian life – giving and praying and fasting – and as we do, awaken in us, use them to awaken in us a deeper and deeper longing, a thirst for You, for more of You, for more of Your presence and power and blessing, for more of Your glory to be seen, and for more of Your kingdom to come. For we ask this all in Your holy name, amen.

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