The Christian Bible Reference Site

What Does the Bible Say About Fasting?

Frequently Asked Questions

What is Fasting?

Fasting means self-denial by going without food for a period of time. Fasting may be total or partial -- avoiding certain foods or eating smaller than normal quantities. The origin of fasting as a religious practice is unclear, but both the Old and New Testaments of the Bible mention a number of instances of fasting for various reasons.

Reasons for Fasting

Distress and Grief

Loss of appetite is a natural reaction in times of distress, grief and mourning, and fasting was considered appropriate at these times. David fasted as a sign of grief when Abner was murdered (2 Samuel 3:35). There was a seven-day fast at the death of Saul (1 Samuel 31:13). As the apostle Paul was being transported to Rome as a prisoner the ship was caught in a violent storm. Fearing death, those aboard did not eat for many days (Acts 27:18-20, 33-34).

Spiritual Preparation

Fasting is a self-sacrifice that makes one humble and more accepting of God's will. Moses fasted for forty days in preparation for receiving the Ten Commandments (Exodus 34:28). Daniel fasted for three weeks before receiving his vision (Daniel 10:2-6). Elijah fasted forty days before speaking with God (1 Kings 19:8). Jesus fasted for forty days in preparation for His temptation by the devil (Matthew 4:1-11, Luke 4:1-13).

In both the Old and New Testaments, fasting is seen as useful for humbling oneself as a sign of commitment or repentance and for increasing faith, especially when accompanied by prayer. Fasting allowed one to be devoted to spiritual matters without distraction from earthly things. However, fasting was not to be considered an end in itself, nor a substitute for obedience to God and doing good deeds (Isaiah 58:3-10).

Repentance and Atonement

When Jonah predicted the downfall of Nineveh, The Ninevites fasted as a sign of repentance in hopes God would spare their city (Jonah 3:3-9). The Day of Atonement was an annual obligatory day of rest and fasting for the Israelites (Numbers 29:7). When the Israelites had sinned, they often humbled themselves and fasted in hopes of regaining God's favor (Judges 20:26, 1 Samuel 7:6).

Jesus' Teachings on Fasting

Jesus said that fasting, like prayer, should be done in private and not for show (Matthew 6:16-18, cf., Matthew 6:5-7). John the Baptist's disciples routinely fasted according to Jewish custom, but Jesus' disciples did not. However, Jesus said His disciples would mourn and fast after He had left them (Matthew 9:14-15; Mark 2:18-20; Luke 5:33-35). The early Christians practiced fasting at least occasionally (Acts 13:3, 14:23, 2 Corinthians 6:5, 11:27).

Omitted Verses

Some older Bible versions mention fasting in these verses:
21 Howbeit this kind goeth not out but by prayer and fasting. (KJV 1900, Matthew 17:21)

29 And he said unto them, This kind can come forth by nothing, but by prayer and fasting. (KJV 1900, Mark 9:29)

30 And Cornelius said, Four days ago I was fasting until this hour; and at the ninth hour I prayed in my house, and, behold, a man stood before me in bright clothing, (KJV 1900, Acts 10:30)

5 Defraud ye not one the other, except it be with consent for a time, that ye may give yourselves to fasting and prayer; and come together again, that Satan tempt you not for your incontinency. (KJV 1900, 1 Corinthians 7:5)

However, those fasting references are believed to be later additions that were not in the original Bible manuscripts.1 Thus, the fasting references are omitted in modern translations (Matthew 17:21, Mark 9:29, Acts 10:30, 1 Corinthians 7:5).

Fasting Not Required

Despite the tradition of fasting in the Bible, and Jesus' references to it, the New Testament teachings do not require fasting, and neither Jesus nor His disciples made fasting obligatory. However, a tradition of partial fasting on Wednesdays, and especially on Fridays dates back to the early days of Christianity.

Church Traditions

Church teachings about fasting vary. Many Catholics observe partial fasting traditions during Lent (the period between Ash Wednesday and Easter). Orthodox Christians observe even more fasting days. Most Protestant churches do not have any firm rules or traditions about fasting.

Health Effects

The partial and token fasts observed by some churches are not known to cause health problems. However, more severe fasting regimens could result in an array of health problems and even death.2,3 Medical advice is recommended before beginning a fasting program.  

1Wood, D. R. W., & Marshall, I. H. (1996). New Bible dictionary (3rd ed.) (364). Leicester, England; Downers Grove, IL: InterVarsity Press.
2American Cancer Society, Fasting, http://www.cancer.org/
3National Health Service (UK), Fasting: Health Risks, http://www.nhs.uk/