Short answer: In Matthew 6:16–18 Jesus says "when you fast," not if, so fasting is assumed among his disciples. His concern is motive and audience: the hypocrites disfigure their faces to be seen fasting by people, while the disciple anoints the head and washes the face so as not to be seen by men but by the Father who sees in secret. Jesus gives no schedule, length or method, and attaches no promised result to fasting itself. He places it among the quiet practices of a heart already turned toward God rather than toward human approval.
Where fasting fits in the sermon on the mount
Matthew 6:16–18 sits inside the Sermon on the Mount, Jesus' extended instruction to his disciples about life under God's rule. It is teaching, not story, and it arrives in a run of matched sayings about religious practice: giving, then prayer, then fasting. Each saying follows the same shape. Jesus names how the hypocrites act, tells the disciple how to act instead, and ends with the Father who sees in secret and rewards. The repetition is deliberate. Fasting is placed among ordinary devotion, not set apart as an elite discipline for a spiritual few.
The sayings before these verses concern prayer. Jesus has warned against praying to be seen by people and has taught his disciples to address God as their Father in secret. The sayings after turn to treasure, warning that earth's stores are consumed and stolen while heaven's are not. Read together, the whole section asks two questions: who is watching, and what are you storing up? Fasting belongs to a life investing in heaven rather than in a reputation on earth. The law required one annual fast day, but Jesus does not legislate here. He assumes a voluntary practice and regulates its motive.
The contrast pattern carries the meaning. The hypocrites disfigure their faces so that others will notice they are fasting, and Jesus says they have received their reward: the attention is the whole payment. The disciple is told to anoint the head and wash the face, ordinary grooming that hides rather than advertises the fast. The Father sees what is hidden and will reward it. Two cautions belong with this text. Jesus is not promising that every fast brings visible benefit, and no rule of fasting should override care for the body or medical advice, especially where illness or a history of disordered eating is present.
What Jesus says about fasting and being seen
Jesus begins with the words "Moreover when you fast," which assumes his hearers already fasted. He does not argue for the practice or explain how often to do it; he takes it for granted and then shapes how it is done. The fasting in view is going without food for a set time for a religious purpose. That the text never defines it further is worth noticing: Jesus treats it as a known habit of devout life, not an innovation. His concern here is not whether people fast but what they are after while they fast, and who they are hoping will notice.
The contrast is with the hypocrites, people acting a part. They disfigure their faces, making themselves look grim or neglected on purpose, so that others will conclude they are devout. Jesus calls this staging, and then says of them, "Most certainly I tell you, they have received their reward." The human notice they wanted is the whole payment; nothing further is owed. Over against that, he tells the person fasting to anoint the head and wash the face, ordinary grooming that hides the fast from onlookers. The fast becomes visible to the Father who sees in secret, not to the room.
The promise attached is deliberately general: the Father who sees in secret will reward you. Jesus does not say what the reward is, and we should resist filling in health, breakthrough, or a measurable return. The point is that unseen devotion is not unseen by God. Two cautions belong with this text. First, secrecy can itself become a performance, so the aim is honesty before God rather than a technique. Second, fasting involves the body, and no rule of fasting should override care for the body or medical advice, especially with conditions such as diabetes or a history of disordered eating.
Finally, this teaching sits inside grace, not outside it. The Father who sees in secret is already the Father of those who pray to him, and the reward he gives is his to define. Our part is not to purchase his attention by looking miserable or by telling no one, but to live honestly before the one who already sees.
Fasting for the Father who sees in secret
Jesus opens with the words “Moreover when you fast” (6:16). The wording treats fasting as something his disciples already do. He does not argue for the practice or set a calendar for it; he assumes it and goes straight to motive. The hypocrites in view make their faces sad and disfigure them so that others will notice. Jesus says plainly that they have received their reward. The contrast in 6:17–18 is quiet and ordinary: anoint your head, wash your face, look normal. Fasting is to be seen by your Father who is in secret, not by the people around you.
The placement matters. Just before this, Jesus warns against praying to be seen and teaches the disciples to address God as Father in secret. Just after, he turns to treasure stored on earth or in heaven. Giving, praying and fasting share one shape and one warning: display collects its reward now, while hidden devotion is left to the Father. The treasure sayings show where fasting belongs, in a life investing in heaven rather than in a reputation. The law required one annual fast day, but this text legislates nothing; it assumes a voluntary practice and regulates its motive.
Notice what Jesus does not promise. He attaches no schedule, no length, no method and no guaranteed result to fasting. He names a Father who sees, and leaves the outcome to him. That keeps fasting from becoming a technique for extracting something from God. It also means no rule of fasting should override care for the body. People with diabetes, a history of disordered eating or other medical conditions should seek medical advice, and skipping food is never a test of faith. The heart of the passage is audience: fast before the Father, not before an audience.
Fasting, hiddenness, and the reward the text leaves undefined
Jesus assumes his disciples will fast, but the sentence is not a command. He says when you fast, then spends his words on how, not on whether. The contrast is with the hypocrites, who disfigure their faces so that others will notice. Jesus tells his followers to anoint the head and wash the face, ordinary grooming that hides the practice rather than advertising it. The warning targets calculated performance, not every visible sign of sorrow. A believer who looks tired after a long night of prayer is not the person described here. The person described here is arranging appearances so an audience will draw a conclusion.
Where careful readers part ways is what else this establishes. Some read the assumed practice as a continuing pattern for the church and commend regular fasting. Others treat fasting as a wisdom practice, genuinely useful but not commanded under the new covenant, since this text gives no command, no day, and no rule. The disagreement is real and worth naming plainly. What stays central across both views is direction: fasting is aimed at the Father, not at an audience. The text also leaves the reward undefined. Some hear a general promise of God's favor toward hidden obedience; others hear only the opposite of the hypocrites' received payment. Jesus does not say what the reward is, and we should not fill that in for him.
One practical limit belongs here. Fasting can harm people with diabetes, and it can feed a history of disordered eating. No teaching about hidden devotion should override care for the body or the advice of a doctor. The Father who sees in secret is not honored by damage done in secret. Where fasting is unsafe, other hidden disciplines carry the same direction of heart: prayer, giving, quiet service. The passage presses one question on every reader. Is this practice for the Father, or for the people who might notice? God sees what is hidden, and that is enough.
Fasting in secret before the Father who sees
Jesus has just finished teaching his disciples to pray, and he moves straight to fasting as a normal practice, not an optional extra. He does not argue that fasting is wrong. He assumes his followers will do it, the way he assumes they will give and pray. What he targets is the performance: sad faces, disfigured faces, a hunger arranged so others will notice. The hypocrites he describes are not insincere about fasting; they are sincere about being seen. Their reward is the attention they wanted, and it is paid in full. Jesus sets beside that a quiet alternative: wash your face, anoint your head, look ordinary, and let the hunger be known only to God.
The one giving this instruction is the one who fasted forty days in the wilderness and refused to make his hunger a spectacle or a lever for testing the Father's care. He knows what fasting exposes, and he names it plainly. Fasting can become a way of asking people to admire us, and the appetite for approval runs deeper than the appetite for food. The gospel answer to that appetite is not stronger willpower but grace. The Father who sees in secret is already looking, already attentive, and the disciple's standing rests on his regard rather than on a religious performance put on display.
Notice where this sits in the Sermon. Jesus has just tied forgiveness to the Father's forgiveness, and he will go on to warn about treasure on earth. Both assume a heart already being reordered by God, not a heart earning its welcome. Fasting belongs inside that reordering, and it never earns forgiveness. It is also a bodily practice, and some bodies cannot safely go without food. Diabetes, a history of disordered eating, pregnancy, or medication schedules can make fasting harmful. No rule about fasting should override care for the body or the advice of a doctor. The Father who sees in secret is not impressed by damage done in his name.
Fasting that only your Father sees
Jesus assumes his disciples will fast, and the whole instruction here concerns how they do it. The hypocrites in view make their fasting visible: sad faces, disfigured features, a performance aimed at an audience. Jesus does not forbid fasting, he forbids fasting as display. His alternative is almost comically ordinary. Anoint your head, wash your face, look like a normal person going about a normal day. The practical test is simple: would this practice still make sense if no one ever knew about it? That test removes the announcement, the conspicuous fatigue, and the post that quietly requests admiration. Fasting is aimed at God, and God is described as the one who sees in secret.
Because the audience is God and not people, the form and length of a fast are matters of freedom rather than law. A believer may choose a time, a way of abstaining, and a duration, and none of those choices should be treated as the only faithful option. What matters is that the practice is voluntary, deliberate, and directed to the Father. This text promises no particular outcome such as healing, breakthrough, or an answered request. It promises only that the Father sees, and it leaves the reward to him. That is enough to rest on, and it keeps fasting from becoming a technique for extracting results.
Two cautions belong with this teaching. First, fasting can harm people with medical conditions such as diabetes or a history of disordered eating, and no rule of fasting should override care for the body or medical advice. Second, fasting is never a standalone achievement. The same sermon ties the Father's forgiveness to our forgiving others, so a fast that ignores mercy toward a person we resent is out of tune with the prayer it accompanies. Grace is the ground of any obedience here. We fast because we are already seen and known, not to earn the seeing.
Finally, this discipline belongs in ordinary life, not on a stage. A believer might set aside a meal and give the time to prayer, or abstain from something else that occupies attention, and then go to work looking entirely unremarkable. If someone asks, there is no need to advertise a secret. The Father who sees in secret is the whole audience this practice needs, and leaving the reward in his hands frees us from measuring ourselves against anyone else's devotion.
Biblical fidelity check
Matthew 6:16–18 sits inside Jesus' teaching on religious practice, right after his words on forgiveness in 6:14–15 and just before his warning about earthly treasure in 6:19–20. He assumes fasting is happening ("when you fast," not if), then contrasts staged devotion with hidden devotion. Read carefully, the passage resists two mistakes: treating the reward as a formula for guaranteed blessing, and treating the warning as a ban on all outward seriousness. The grim face Jesus describes is a calculated performance, a face arranged so others draw a conclusion about the person's devotion.
Evangelical readers agree Jesus forbids fasting for human applause, but differ on what else is established. Some see the assumed practice as a continuing pattern and commend regular fasting; others treat it as wisdom, useful but not commanded, since no command, day, or rule appears. Readers also differ on the reward, which the text leaves undefined, and on whether all outward expression is forbidden or only the performance. What stays central is that fasting is directed to the Father, not an audience, and God sees what is hidden.
Following the theme of Matthew 6:16-18 through Scripture
Fasting sits beside giving and prayer in this chapter, so read the wider passage to see the shared pattern of secret devotion. Then trace fasting through the rest of Scripture with Jesus Denounces Hypocrisy in Matthew 23, consider what Jesus says about food and the heart in Matthew 1: Genealogy and Birth of Jesus, weigh the warnings of Matthew 10: Jesus Sends the Twelve with Authority, and let Matthew 12: Lord of the Sabbath and Sign of Jonah show how the practice fits a life aimed at the Father's approval.
Frequently asked questions
Does the Bible command Christians to fast, or is it voluntary?
In this passage Jesus does not command fasting; he assumes it will happen and regulates how it is done. He says "Moreover when you fast" (Matthew 6:16), addressing those who fast rather than requiring everyone to. The command he gives is about motive: do not fast to be seen by men, but before your Father who sees in secret. So fasting is voluntary here, yet it is expected and must be done humbly, not for display.
Why did Jesus tell people to wash their face and not look sad when they fast?
Jesus said this because fasting is meant to be seen by God, not performed for an audience. In 6:16 he describes hypocrites who disfigure their faces so others will notice they are fasting, and he says they have already received their reward. Instead, in 6:17–18, he tells his hearers to anoint their head and wash their face so the fasting stays hidden, and the Father who sees in secret will reward them. The point is not grooming itself but who is watching.
When I fast without anyone knowing, what reward does God actually give me?
Jesus does not name the reward; he simply promises that your Father, who sees in secret, will reward you (Matthew 6:18). The point of the verse is the contrast: the hypocrites who fast for an audience receive their reward in that audience's notice, while the hidden fast is seen by God and answered by him. The passage leaves the content of the reward with the Father, so we trust his judgment rather than measure an outcome. What is clear is that the fast is directed to God, not performed for people.
