Fasting in the Bible is a setting aside of time to abstain from food to repent from sin and seek God. We see this practice span both Old and New Testaments. What follows here is a brief overview of the practice in each testament.
Fasting in the Old Testament
In the Old Testament, fasting is often linked with prayer and/or penitence, showing a response of genuine humility and repentance for sin, either by an individual or by the nation. People sometimes accompany their fasting with mourning, sackcloth, and ashes (Psalm 35:13; Isaiah 58:5).
The first reference to fasting is found in Exodus 34:28, where Moses fasts for forty days and nights on Mount Sinai to identify with his people and to repent on their behalf so they would not be destroyed (Exodus 32; Deuteronomy 9-10).[1] People would fast as they wept before God and presented Him with offerings (Judges 20:26). Fasting would accompany confession of sins (1 Samuel 7:6; 2 Samuel 12:16-17; 1 Kings 21:27-29) in order to avert God’s wrath (Jonah 3:6-10) or to be saved from the enemy (Esther 4:16).
Every year, the Jews would fast on the Day of Atonement (Leviticus 16:19-29-31; 23:27-32) for the cleansing of their sins. Leviticus 16:29-31 (NIV) describes the annual fast:
“This is to be a lasting ordinance for you: On the tenth day of the seventh month you must deny yourselves and not do any work—whether native-born or a foreigner residing among you—because on this day atonement will be made for you, to cleanse you. Then, before the Lord, you will be clean from all your sins. It is a day of sabbath rest, and you must deny yourselves; it is a lasting ordinance.”
“Moses fasts for forty days and nights on Mt. Sinai to identify with his people and to repent on their behalf so they would not be destroyed.”
The Day of Atonement required both nationals and foreigners to deny themselves as well as rest for repentance and purification.[2] The Hebrew phrase (centering on the verb anah) has been translated as “deny yourselves” (NIV, NLT, NSRV), “humble yourselves” (NASB, NET), “afflict yourselves” (ESV, RSV), and “afflict your souls” (KJV, ASV) and has been traditionally understood as fasting.[3]
Fasting in the New Testament
The New Testament word for fasting is the Greek word nesteuo (occurring 20x in the New Testament), meaning to “fast,” to “go without food,” or to “abstain from food.” In Matthew 9:14-17, the Pharisees criticized Jesus for not taking religion seriously, using His disciples’ lack of fasting as evidence. Yet Jesus responded not by being dismissive of fasting (He Himself fasted) but by using a metaphor: it did not make sense for wedding guests to mourn while the groom was with them (Mark 2:18-19; Matthew 9:14-17). He would be taken from them, and then they most certainly would fast.
Again, Jesus is not against fasting, for even before He began his public ministry, He went into the wilderness and fasted for forty days (see Matthew 4:1-11). We see profound theological and prophetic significance in Jesus’ forty-day fast. Just as Moses fasted forty days for his people, and Elijah to hear God’s whisper, Jesus fasted to obey His Father and prepare for His earthly ministry. What was unparalleled about Jesus’ fast was that there was no connection with personal repentance, for He was sinless. Rather, it was for the preparation and inauguration of His extraordinary mission to save the world.
Led by the Spirit into the wilderness, Jesus through His prolonged fast feasted on the presence of His Father, depending on Him alone, focusing on His goodness in solitude. Jesus was teaching us to fast in secret, to deepen our relationship with His Father.
“Jesus through His prolonged fast feasted on the presence of His Father, depending on Him alone.”
Jesus’ fast also represents His deep identification with humanity—as His hunger highlights his true humanity. When he was tempted by Satan, He overcame each temptation through the Scripture, mostly quoting Deuteronomy. So, where the first Adam failed, the second Adam conquered, and we conquer through Him. In the intense hunger, Jesus showed that spiritual nourishment holds greater value than any earthly desire, when one is focused on God and His mission.
This spiritual nourishment is what Jesus likely had in mind when He promised those who fast rewards from their Father in heaven (see Matthew 6:16-18). They were to do it for God in secret—not to be seen as pious by people. In this passage, Jesus presupposed that His disciples would fast (“and when you fast”), but He wanted them to do it for the right motivation—for God. By saying “when” or “whenever,” Jesus was not enforcing a particular time, pattern, or method for fasting. Rather, He was concerned with fasting’s motive, as a matter between a person and God.[4]
In the book of Acts, we see that the early church fasted when they chose church leaders and when they sent out disciple makers for the global mission (Acts 13:2-3; 14:23).
When You Fast
It is important to remember that Christian fasting is a voluntary act of love for God. God’s love for us is not controlling but redemptive. And for those with health concerns, you must approach fasting with wisdom and care. Also, fasting does not mean punishing ourselves but rather building endurance by letting the Holy Spirit control our worldly appetites so nothing is standing between our uninterrupted communion with the Father.
When you decide to fast, just so you know, you will feel hungry. Your brain may panic a bit. Your stomach may growl/roar/scream to remind you “I am hungry.” And that’s okay!
If you have never fasted or have fallen out of practice, I recommend you start by planning your fast. Choose the day, date, time, and hours. Don’t overcommit. Begin with short fasts like skipping a meal once or twice a week to build endurance. During fasting, incorporate Scripture readings, devotions, journaling, and praying to guard against distractions.
Remember that in fasting, God may expose some of your unhealthy habits or sins. Use this opportunity to ask for forgiveness and a renewed heart. Also, choose a purpose for your fast and let God address it. But try not to manipulate Him to act within a set time frame. Instead, pray for trust and peace.
“Use this opportunity to ask for forgiveness and a renewed heart.”
Additionally, if possible be among people. While there have been some mighty ascetics who withdrew from communities to fast, Jesus did not condemn social interactions but insisted on looking normal outside by yoking with God inside. Avoid gossip, malice talk, or anything unholy. Even consider group fasting to seek God’s blessings, forgiveness, and help together.
I began fasting last year while taking a spirituality class by skipping meals, often in remembrance of those who lack food. This practice sparked a deeper commitment, and I eventually fasted for longer hours with a specific purpose in mind—such as wisdom to write some deep theology papers, deal with finances, or navigate the Christian life. Looking back, I see none of those prayers and fasts were in vain. God who sees in secret rewards in abundance.
[1] Douglas Stuart, Exodus: An Exegetical and Theological Exposition of Holy Scripture, Volume 2, The New American Commentary (Nashville: Broadman & Holman Publishers, 2006), 735.
[2] Gordon J. Wenham, The Book of Leviticus, New International Commentary on the Old Testament (Grand Rapids: W.B. Eerdmans, 1979).
[3] M. F. Rooker, Leviticus An Exegetical and Theological Exposition of Holy Scripture, Volume 3, The New American Commentary (Nashville: Broadman & Holman, 2000), 223.
[4] Leon Morris, The Gospel according to Matthew, The Pillar New Testament Commentary (Grand Rapids: William B. Eerdmans Publishing Co., 1992), 150.
