# What does the Bible say about fasting?

> What the Bible says about fasting — Scripture on prayer and humility, not a diet plan, with health caveats and no invented schedule, plus one next step.

Source: https://www.lumin.faith/what-the-bible-says-about/fasting
By Andrew Kittridge, Founder of Lumin · September 6, 2026
Verses are chosen for the question being asked. Topic pages quote the King James Version (public domain). The public reader and iPhone Bible tab use the Lumin Translation, rendered from Hebrew and Greek with AI and then checked for clarity and fidelity. Glosses in answers are original summaries, not a second Bible. Open the named passage; AI is not the interpreter. [How we cite Scripture](https://www.lumin.faith/about#how-we-cite)

Fasting in Scripture is a spiritual practice joined to prayer, repentance, and seeking God — not a diet protocol and not a contest. Jesus assumes his people will fast, and he warns them not to perform it. Isaiah 58 refuses a fast that oppresses workers while looking pious. If you are pregnant, ill, or otherwise at medical risk, ask a clinician, not an app. Lumin will not prescribe a schedule or shame you for not fasting.

## Fasting in the Bible

- **Matthew 6:16-18** — When you fast, do not look miserable for an audience; your Father who sees in secret will reward you.
- **Matthew 4:1-2** — Jesus fasted forty days and nights and was hungry — a temptation narrative, not a DIY challenge.
- **Isaiah 58:3-7** — The fast God chooses looses bonds of wickedness and shares bread with the hungry, not empty ritual.
- **Joel 2:12-13** — Return to God with all your heart, with fasting; rend your hearts, not your garments.
- **Nehemiah 1:4** — Nehemiah weeps, mourns, fasts, and prays over Jerusalem.
- **Matthew 9:14-15** — When the bridegroom is taken away, then they will fast.
- **Acts 13:2-3** — The church worships and fasts; the Spirit sets apart Barnabas and Saul; they fast and pray, then send them.
- **Zechariah 7:5-6** — Were your fasts for me — or for yourselves? Motive matters more than the calendar.

## Highlighted verse

> That thou appear not unto men to fast, but unto thy Father which is in secret: and thy Father, which seeth in secret, shall reward thee openly.
>
> — Matthew 6:18 (King James Version)

## Reflection

Biblical fasting shows up in mourning, repentance, danger, and commissioning — Esther, Ezra, Daniel, Nineveh, Anna in the temple, elders appointed with prayer and fasting. Moses’ forty days is theophanic narrative, not a challenge to copy. Jesus’ forty days is his, not yours to scale. The through-line is humility before God, usually with prayer, never as a way to buy an outcome or a thinner body.

Wisdom includes limits. Competitive fasting, weight-loss promises, and mandatory programs are not in these texts. 1 Corinthians 7:5 speaks of temporary abstinence by agreement in marriage for prayer — not a general diet rule. If fasting would harm your body, do not. If you fast, keep it quiet, keep it joined to prayer and mercy, and keep it under the care of your church. Lumin’s Pray page can sit beside the prayer; it is not a medical coach.

## One next step

Read Matthew 6:16-18 and Isaiah 58:3-7. If you and your pastor agree a simple fast is wise and medically appropriate, keep it secret and pair it with prayer — not with a public announcement or a calorie goal.

## FAQ

### What is a key Bible verse about fasting?

Matthew 6:16-18: when you fast, do not perform it for an audience; your Father who sees in secret will reward you. Isaiah 58:3-7 describes a fast God chooses — justice and bread for the hungry, not empty ritual. Joel 2:12 joins fasting to returning with the whole heart.

### How should Christians fast?

Quietly, joined to prayer and repentance, under the wisdom of your church, and never as a diet or a contest. Jesus assumes fasting; he does not assign a mandatory calendar. If fasting would harm your body, do not. Ask a clinician when health is in question — not an app.

### Is fasting in the Bible a weight-loss plan?

No. Biblical fasting is humility before God, often in mourning, repentance, or commissioning. It is not a calorie protocol, a forty-day challenge copied from Moses or Jesus, or a reason to shame people who do not fast.

## Related questions

- [What does the Bible say about prayer?](https://www.lumin.faith/what-the-bible-says-about/prayer.md)
- [What does the Bible say about humility?](https://www.lumin.faith/what-the-bible-says-about/humility.md)
- [What does the Bible say about church?](https://www.lumin.faith/what-the-bible-says-about/church.md)

## Related guides

- [Make room to pray](https://www.lumin.faith/pray.md)
- [Ask with Scripture you can open](https://www.lumin.faith/ask.md)
- [Read the chapter with Bible Coach](https://www.lumin.faith/bible-coach.md)
- [The Lumin Covenant](https://www.lumin.faith/trust.md)


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Answered by Lumin, a Christian AI app for iPhone and iPad that gives short, Scripture-cited
answers with one next step. https://apps.apple.com/us/app/lumin-bible-ai-companion/id6754889412