What Does the Bible Say About Fasting?
When ye fast — not if. The forgotten discipline Jesus assumed, and how Scripture says to practise it.
Jesus said “when ye fast,” not if (Matthew 6:16) — assuming the practice while forbidding the performance: “anoint thine head, and wash thy face,” fasting to the Father “which seeth in secret.” Biblical fasting is voluntarily setting food aside to seek God with sharpened hunger — for guidance, repentance, or intercession — and Isaiah 58 insists it must walk with justice and mercy to mean anything.
A hunger aimed at God
Fasting appears at the Bible’s hinge moments: Moses on the mountain, Nehemiah before rebuilding, Esther before the throne room, Jesus forty days in the wilderness, the church at Antioch before its first missionaries sailed. The pattern: when the need outweighs the appetite, God’s people let the stomach preach to the soul. Emptiness becomes attention; the hunger pang becomes a prayer bell.
And when he had fasted forty days and forty nights, he was afterward an hungred.
As they ministered to the Lord, and fasted, the Holy Ghost said, Separate me Barnabas and Saul for the work whereunto I have called them. And when they had fasted and prayed, and laid their hands on them, they sent them away.
Secret, not showy
Jesus’ one rule for fasting is privacy of intent: no disfigured faces advertising devotion — the Father who sees in secret rewards openly. Fasting has no merit as a hunger strike against heaven; it earns nothing. It is expression, not extraction: sorrow for sin (Joel’s “rend your heart”), urgency in seeking, weaning from the tyranny of appetite. The audience of one is the entire point.
But thou, when thou fastest, anoint thine head, and wash thy face; 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.
Therefore also now, saith the LORD, turn ye even to me with all your heart, and with fasting, and with weeping, and with mourning:
The fast God chooses
Isaiah 58 is the Bible’s fasting audit: a people fasting punctiliously while exploiting workers heard God redefine the discipline — is not this the fast that I have chosen? to loose the bands of wickedness, deal bread to the hungry, cover the naked. Abstinence that coexists with injustice is theatre. Real fasting empties the plate and opens the hand.
Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke? Is it not to deal thy bread to the hungry, and that thou bring the poor that are cast out to thy house? when thou seest the naked, that thou cover him; and that thou hide not thyself from thine own flesh?
And Jesus said unto them, Can the children of the bridechamber mourn, as long as the bridegroom is with them? but the days will come, when the bridegroom shall be taken from them, and then shall they fast.
Quick answers
- Are Christians required to fast?
- No command sets frequency, but Jesus assumed his people would fast (“when ye fast,” Matthew 6:16; “then shall they fast,” Matthew 9:15). It is a voluntary discipline — commended, modelled, never legislated.
- What should I fast from — only food?
- Biblical fasting is from food (sometimes food and drink, briefly). The principle — setting aside a legitimate pleasure to seek God — is applied by many today to other appetites; 1 Corinthians 7:5 already extends it beyond the table.
- How do I start fasting?
- Begin small (a meal, a day), pair every hunger pang with prayer, keep it secret (Matthew 6:17–18), keep mercy in it (Isaiah 58), and mind health — the discipline serves seeking God, never harming the body he made.
