What is fasting, and should Christians fast?

The Master's Expectation

Jesus Assumes His Followers Will Fast in Secret

“When you fast, do not look somber as the hypocrites do, for they disfigure their faces to show others they are fasting. Truly I tell you, they have received their reward in full.

Matthew 6:16 (NIV)

Jesus says 'when you fast' rather than 'if,' establishing fasting as an ordinary duty alongside giving and praying while condemning public hypocrisy.

When Jesus addressed fasting in the Sermon on the Mount, He did not offer a tentative suggestion; He established a quiet expectation for the Christian life. Opening with Matthew 6:16, Jesus taught His disciples regarding their conduct: “When you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others.” The Savior never said if you fast, but when you fast. He placed this inward, bodily discipline on the exact same footing as generous giving and secret prayer. Yet precisely because fasting deals with physical appetite and self-denial, human pride readily hijacks it for theatrical display. The hypocrites in the streets longed for the applause of men, disfiguring their features to broadcast their supposed holiness, and Jesus declared with finality that such worldly recognition is the only reward they will ever receive.

To rescue fasting from hypocrisy, Christ provided a striking counter-cultural command. In Matthew 6:17, He directed His followers to anoint their heads and wash their faces. The disciple's outward demeanor should resemble someone preparing for a feast rather than advertising an ordeal. The purpose of this intentional washing is laid out in Matthew 6:18: fasting is conducted not to be seen by mortals, but to be laid before your Father who is in secret. True spiritual disciplines are meant for an audience of One. The heavenly Father sees into the quiet, hidden chambers of the human heart, and He promises to reward openly those who seek Him without pretense. In stark contrast to this humble posture stands the religious arrogance exposed in Luke 18:12, where the self-righteous Pharisee boasted before God that he fasted twice a week. That man went down to his house unjustified, for God detests religious ritual deployed as an instrument of self-congratulation.

The Bridegroom and the Fast

A Discipline Reserved for the Bridegroom's Absence

Jesus answered, “How can the guests of the bridegroom mourn while he is with them? The time will come when the bridegroom will be taken from them; then they will fast.

Matthew 9:15 (NIV)

Jesus explains that while wedding guests celebrate with the Bridegroom present, his disciples will fast once he is taken away.

The unique character of Christian fasting is rooted directly in the presence, departure, and promised return of Jesus Christ. When critics questioned why the disciples of John the Baptist and the Pharisees engaged in regular ascetic fasts while Christ's companions ate and drank, Jesus answered with the metaphor of a wedding in Matthew 9:15. He asked, “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.” The incarnation of Christ brought the very presence of God into human history. While the Bridegroom walked among them, feasting and rejoicing were the only fitting responses to the dawn of the Messianic age.

This same principle is preserved across the Synoptic Gospels. In Matthew 9:14, John's disciples voiced genuine confusion over the festive joy surrounding Jesus' followers. The parallel account in Mark 2:18 and Luke 5:33 reveals that the religious community expected rigorous adherence to customary, outward fasts. Yet in Mark 2:19 and Luke 5:34, Jesus pressed the wedding analogy once more, asking how companions of the bridegroom could possibly mourn while celebrating by His side. Fasting while the Lord of glory stood in their midst would have denied the very joy of His presence.

Everything changed, however, when the Bridegroom was taken away. As Jesus warned in Mark 2:20 and reiterated in Luke 5:35, days were approaching when Christ would be seized, crucified, and taken up into heaven. In this present interim age—between His ascension and His glorious physical return—fasting is the natural posture of the church. We fast today not out of legalistic bondage, but out of an aching love for our absent King, setting aside earthly bread because our deepest spiritual hunger is for the day when the Bridegroom returns.

True Versus False Fasts

God Rebukes Hypocrisy and Requires Heartfelt Righteousness

“Is not this the kind of fasting I have chosen: to loose the chains of injustice and untie the cords of the yoke, to set the oppressed free and break every yoke?

Isaiah 58:6 (NIV)

God defines the true fast not as outward gloom, but as breaking unjust bonds and caring for the afflicted.

Throughout biblical history, God has consistently unmasked the hollow performance of empty religious ritual. The prophet Isaiah delivered God's burning indictment against outward piety divorced from personal integrity in Isaiah 58:6, revealing the Lord's chosen discipline: “Is not this the fast that I choose: to loose the bonds of wickedness, to undo the straps of the yoke, to let the oppressed go free, and to break every yoke?” The people of Judah had complained bitterly in Isaiah 58:3, asking why God ignored their abstinences, but God exposed their underlying hypocrisy: on the very days they abstained from food, they pursued selfish profit and brutally exploited their laborers.

In Isaiah 58:4, God declared that fasting accompanied by strife, bitter debate, and violent contention will never cause a voice to be heard in heaven. Outward displays of humiliation—such as drooping the head like a bulrush or sprawling across sackcloth and ashes (Isaiah 58:5)—are thoroughly repulsive to God when the heart remains stubborn and callous. According to Isaiah 58:7, the authentic fast naturally overflows into love for neighbor: breaking bread with the starving, sheltering the homeless outcast, covering the naked, and refusing to turn away from one's own kin.

The historical warnings of the prophets confirm that abstaining from food can never bribe God into overlooking unrepentant sin. Through Jeremiah, the Lord warned that when a rebellious people fast, He will refuse to hear their cries (Jeremiah 14:12), even when an assembly gathers formally as in Jeremiah 36:9. Similarly, Zechariah 7:5 demanded whether the fasts observed throughout the seventy years of Babylonian exile were truly for God, or merely self-pitying displays. Yet when repentance is genuine and righteousness restored, God transforms sorrow; as Zechariah 8:19 promises, the fasts of mournful remembrance are destined to become joyful, cheerful feasts of gladness for the faithful.

Humiliation and Repentance

Old Testament Saints Afflicted Their Souls Before God

So I turned to the Lord God and pleaded with him in prayer and petition, in fasting, and in sackcloth and ashes.

Daniel 9:3 (NIV)

Daniel unites fasting, sackcloth, and ashes with focused prayer to confess the sins of his people and plead for mercy.

When Old Testament saints encountered overwhelming crisis or the conviction of sin, they cast themselves upon God's mercy with fervent prayer and fasting. Daniel modeled this posture in Daniel 9:3: “Then I turned my face to the Lord God, seeking him by prayer and pleas for mercy with fasting and sackcloth and ashes.” Daniel knew that deep repentance demands the deliberate humbling of the whole person before the sovereign majesty of God.

This pattern began at Sinai and the tabernacle. Moses spent forty days and forty nights without bread or water before God (Exodus 34:28; Deuteronomy 9:18). Under the Mosaic covenant, Israel was commanded to afflict their souls annually on the Day of Atonement (Leviticus 16:29; Leviticus 23:27, 32; Numbers 29:7). In national crises, Israel gathered to weep and fast before battle (Judges 20:26; 1 Samuel 7:6), and godly men fasted over the deaths of Saul and Jonathan (1 Samuel 31:13; 2 Samuel 1:12). David pleaded with God for his sick child in tears and fasting (2 Samuel 12:16, 22), chastening his soul even when mocked by enemies (Psalms 35:13; Psalms 69:10; Psalms 109:24). Remarkably, even wicked Ahab found divine respite when he humbled himself in sackcloth (1 Kings 21:27).

God sustained Elijah across a forty-day journey to Mount Horeb (1 Kings 19:8). When mighty armies advanced against Judah, King Jehoshaphat proclaimed a national fast and witnessed deliverance (2 Chronicles 20:3). Ezra led the returning exiles to fast at the river Ahava for safe passage (Ezra 8:21, 23) and mourned over Israel's unfaithfulness (Ezra 10:6). Nehemiah wept and fasted over Jerusalem's broken walls (Nehemiah 1:4; Nehemiah 9:1). Esther called all Jews to abstain from food and drink for three days before she approached the Persian king (Esther 4:16; Esther 9:31). Pagan monarchs recognized this power: Darius fasted throughout the night while Daniel survived the lions' den (Daniel 6:18), and Nineveh's king proclaimed a total fast when Jonah preached, sparing the city (Jonah 3:5, 7). Later, Daniel pursued three weeks of partial fasting seeking understanding (Daniel 10:3). God's clarion call through Joel remains timeless: consecrate a fast, gather the people, and turn to the Lord with all your heart (Joel 1:14; Joel 2:12).

The Apostolic Church

Early Believers Fasted for Guidance, Ordination, and Mission

While they were worshiping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them.”

Acts 13:2 (NIV)

The Holy Spirit directs the church at Antioch to set apart Barnabas and Saul precisely while the leaders are ministering to the Lord and fasting.

The Holy Spirit spoke decisive direction to the leaders in Antioch while they were actively worshiping and abstaining from food, as Acts 13:2 records: "While they were ministering to the Lord and fasting, the Holy Spirit said, 'Set apart for Me Barnabas and Saul for the work to which I have called them.'" Fasting in the New Testament was not an obsolete relic of the Old Covenant; it was the vibrant climate in which the apostolic church sought divine wisdom, made critical decisions, and consecrated servants for mission. Immediately following this word, Acts 13:3 shows the congregation fasting and praying again before laying hands on the missionaries and sending them out. When establishing local leadership across Galatia, Paul and Barnabas mirrored this pattern, committing newly appointed elders to the Lord with prayer and fasting in every church (Acts 14:23).

This apostolic practice rested upon the foundation of Christ's own life and the faithful witnesses who preceded Him. In Luke 2:37, the prophetess Anna served God day and night in the temple with prayer and fasting, welcoming the infant Messiah. Before entering His public ministry, our Lord Himself set the ultimate precedent; both Matthew 4:2 and Luke 4:2 recount that Jesus ate nothing for forty days in the wilderness, anchoring Himself in the Word of God to withstand the devil's assaults. Following his transformative encounter with the risen Christ on the Damascus road, Saul similarly spent three days without sight, food, or drink (Acts 9:9), humbled and praying before his commissioning. Later, in Caesarea, the centurion Cornelius recalled praying and fasting when the angel arrived to direct him to Peter (Acts 10:30).

Throughout his itinerant ministry, Paul embraced intentional hunger as part of his devoted walk with Christ. In 2 Corinthians 6:5 and 2 Corinthians 11:27, he distinguishes between involuntary deprivations like hunger and thirst and voluntary "fastings often," demonstrating that fasting remained a conscious, ongoing discipline throughout his apostolic labors. Even the civil calendar of the Roman world noted Jewish fasts, as seen in Acts 27:9 when Luke remarks that sailing was dangerous because the autumn Day of Atonement fast had already passed. Later during that same voyage, Paul exhorted exhausted sailors who had abstained from food for fourteen days under tempestuous skies to eat and take courage (Acts 27:33). In domestic life, Paul recognized that believers might voluntarily step away even from the blessings of marital intimacy by mutual consent for a specific season to devote themselves wholly to prayer (1 Corinthians 7:5). Taken together, the apostolic records present fasting as a vital, spirit-filled discipline through which the early church consecrated leadership, discerned divine callings, and pursued unbroken communion with God.

Where in the Bible

The story in order

1. Moses fasts forty days (c. 1450 BC) · Exodus 34:28 · Moses' extended fast demonstrates dependence on God during covenant renewal.
2. Day of Atonement established (c. 1450 BC) · Leviticus 16:29 · A foundational annual fast for Israel to afflict their souls before God.
3. David fasts for his child (c. 1000 BC) · 2 Samuel 12:16 · Fasting as an expression of grief and a plea for mercy.
4. Elijah journeys forty days (c. 850 BC) · 1 Kings 19:8 · Divine strength sustains Elijah through an extended fast.
5. Nineveh repents and fasts (c. 760 BC) · Jonah 3:5 · A city-wide fast and repentance in response to God's warning.
6. Isaiah condemns false fasts (c. 740 BC) · Isaiah 58:3 · God rebukes fasting that ignores justice and oppresses others.
7. Jerusalem fasts in exile (c. 600 BC) · Jeremiah 36:9 · A fast proclaimed during a time of national crisis and judgment.
8. Daniel fasts in repentance (c. 530 BC) · Daniel 9:3 · Daniel's extended fast and prayer for Israel's sins.
9. Ezra proclaims a fast (c. 450 BC) · Ezra 8:21 · Fasting to seek God's protection for a perilous journey.
10. Esther calls for a fast (c. 470 BC) · Esther 4:16 · A communal fast undertaken in preparation for a dangerous mission.
11. Jesus fasts forty days (AD 27) · Matthew 4:2 · Jesus' fast in the wilderness prepares Him for ministry.
12. Jesus teaches on fasting (c. AD 30) · Matthew 6:16 · Jesus instructs on sincere, private fasting before God.
13. Early church fasts (c. AD 48) · Acts 13:2 · Fasting accompanies prayer and the Spirit's guidance for missions.
14. Paul's apostolic fasts (c. AD 55) · 2 Corinthians 6:5 · Paul includes fasting among the hardships of his ministry.

True Fasting Versus False

Fasting: A Sign of the Bridegroom's Absence

The Purpose of Fasting

Key words

Fasting

Voluntarily abstaining from food to focus on prayer, repentance, and seeking God. · Matthew 6:16

Afflict their souls (עָנָה (anah))

To humble oneself, often through fasting and repentance, before God. · Leviticus 16:29

Bridegroom

A metaphor for Jesus Christ, whose presence brings joy, and whose absence necessitates fasting. · Matthew 9:15

Repentance

A turning away from sin and toward God, often expressed through fasting. · Daniel 9:3

Sincere

Genuine and unhypocritical, especially in religious devotion and fasting. · Matthew 6:18