Bible Answer

Why do believers fast?

What is fasting, and why do people fast in the Bible?

To fast simply means to abstain from something for a period of time.

Fasting in the Bible generally involve abstaining from all food and drink for a period of a few days or even a week or longer. Some fasts in the Bible lasted as long as 40 days (e.g., Jesus’ 40 days of fasting in the wilderness), though long fasts included drinking water, since the human body cannot live longer than a week without water.

It has become fashionable in recent decades for Christians to engage in lessor forms of fasting (i.e., juice fasts, single meal fasts, etc.), but these practices are not fasts in keeping with the model given in scripture. A scriptural fast involves a complete denial of the flesh (i.e., abstaining from all food and perhaps all drink), thereby triggering a struggle between the will and the flesh. It’s in this struggle that we obtain the spiritual benefit of fasting.

The Bible commonly pairs fasting with praying as essential disciplines of the faith, and while most Christians understand the necessity and importance of prayer, fasting has fallen out of favor among many Christians today. Nevertheless, fasting remains a very important part of a healthy Christian walk, and when we practice fasting as intended, we gain a number of spiritual benefits.

Consider these examples of fasting from scripture: 

Neh. 1:4  When I heard these words, I sat down and wept and mourned for days; and I was fasting and praying before the God of heaven. 
Psa. 35:13  But as for me, when they were sick, my clothing was sackcloth; 
    I  humbled my soul with fasting, 
    And my prayer kept returning to my bosom. 

Dan. 9:3  So I gave my attention to the Lord God to seek Him by prayer and supplications, with fasting, sackcloth and ashes. 
Matt. 17:21  [“But this kind does not go out except by prayer and fasting.”]
Luke 2:37 and then as a widow to the age of eighty-four. She never left the temple, serving night and day with fastings and prayers. 
Luke 5:33  And they said to Him, “The disciples of John often fast and offer prayers, the disciples of the Pharisees also do the same, but Yours eat and drink.” 
Luke 5:34  And Jesus said to them, “You cannot make the  attendants of the bridegroom fast while the bridegroom is with them, can you?
Luke 5:35 “But the days will come; and when the bridegroom is taken away from them, then they will fast in those days.
Acts 13:2 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.”
Acts 13:3 Then, when they had fasted and  prayed and laid their hands on them, they sent them away. 

There are numerous spiritual benefits associated with the practice of fasting, and each of the scriptures quoted above reflects one of those spiritual purposes. 

First, in Nehemiah 1:4 we see fasting associated with an appeal before the Lord, as Nehemiah was appealing for satisfaction from God over a distressing situation in Israel. Fasting is a denial of joy and satisfaction to the physical body, and Nehemiah denied himself to demonstrate to the Lord that he was determined to find no satisfaction apart from God’s mercy in his situation. 

Nehemiah wasn’t attempting to earn God’s favor through his self-denial; he was demonstrating his faith and reliance on the Lord. Just as Abraham acted out of faith to sacrifice his son, Isaac, believing in God’s ability to resurrect, so was Nehemiah showing by his fasting that he trusted the Lord would relieve his anguish provided he sought relief nowhere else - not even relief from his hunger.

Secondly, in Psalms 35, the psalmist says that he humbled his soul by fasting. Fasting is a means of humbling oneself before God because it cleverly exposes our battle with our flesh. During a period of fasting, we experience the flesh’s power to control our will. Though we have declared an intention to abstain from food, nevertheless our body continually wars with our will trying to break our commitment to fast.

This battle with the flesh reveals how powerful the flesh can be, and through this experience we learn humility to resist the flesh's desires. As the battle intensifies during longer periods of fasting, we gain a deeper understanding for the strength of our flesh and the weakness of our will, and we become better at winning that battle. This is the fleshly struggle Paul describes in Romans 7. 

As we learn how to win this battle over our flesh, we are humbling ourselves before the Lord. A humble heart pleases the Lord, as it demonstrates self-awareness of our sin and our unworthiness before the Lord. The Lord is pleased to bless those who demonstrate such humility, and we will naturally become more pleasing to God as we learn how to triumph over the desires of the flesh. 

Thirdly in Daniel 9, Daniel says his attention was directed toward the Lord through a period of fasting. Fasting interrupts our normal routine in a dramatic fashion. When our body is denied the food it expects, our minds are continually reminded of the spiritual reason we are engaged in this ordeal, and in that way our thoughts return to the Lord. As our thoughts return to our relationship with the Lord and our need for His mercy, we enter into a moment of prayer and thus fasting has the effect of bringing us back to God in a regular way.

Fourthly in Matthew 17, the Lord tells the disciples that certain problems in life (e.g., casting out demons from a mute man), are only solvable through prayer and fasting. Notice Jesus says that the solution the disciples were seeking could only come in this way, which means the Lord will not grant relief under lesser circumstances.

As Jesus taught, the Lord has reserved for Himself the power to address certain challenges in life, and when we encounter such circumstances, we must be willing to acknowledge His authority and power before He will act on our behalf. Fasting and prayer are acts of faith that acknowledge God's sovereign control over our lives and circumstances.

Fifth, in Luke 2 we read about the widow who served God in the temple through many years of fasting and prayer in anticipation of the Lord’s arrival. From this example, we learn that fasting is a form of spiritual service to God. Paul says:

Rom. 12:1  Therefore I urge you, brethren, by the mercies of God, to present your bodies a living and holy sacrifice, acceptable to God, which is your  spiritual service of worship. 

Just as the saints of the Old Testament presented sacrifices of animals before the Lord, so is the Christian to present sacrifices today. Our sacrifices take a very different form, however, for we are called to present our bodies sacrificially, Paul says. Fasting is a form of sacrifice to the Lord, where we voluntarily deny ourselves something of value (i.e., food) in thanks for the Lord’s mercy, kindness and provision. 

Fasting doesn't obtain or earn the Lord’s kindness (i.e., it is not a quid pro quo). Rather, our fast is a thanks offering to the Lord through our bodies. We cannot give the Lord anything He doesn’t already own, so our gifts of thanks to Him must take the form of personal sacrifice (i.e., a denial of self) rather than an enrichment of God. In this sense, fasting can be a simple yet powerful way to extend a blessing of thanks to the Lord through sacrifice.

Sixth, in Luke 5 the Pharisee criticized Jesus’ disciples for not fasting, when it was customary for students of all rabbis to fast regularly. Jesus answered the critic by saying so long as He remained on earth, His disciples had no reason to fast, but once He departed, then the disciples would fast regularly.

In this exchange, we find yet another spiritual purpose in fasting. Fasting serves as a reminder that our life lived on earth apart from Christ will be one of trials and persecution and even sorrow. While our lives also include moments of joy, we must await the Lord's return and His kingdom before we will know true, eternal joy. 

Therefore, the New Testament continually reminds the believer not to become content with the joy of this world, knowing the world and all it contains is destined to burn up. For example, we’re told believers are not of the world (John 15:19), we are wanderers in a land that is not ours (Heb 11:13), and we should not store up our treasure on earth (Matt 6:19).

Nevertheless, our flesh enjoys the lusts of life, so we need regular reminders that the pleasures of this life are not to be confused with the joy that comes in Christ alone. Saints are called to fast regularly as a reminder and acknowledgement of the deprivation and wanting that accompanies our time of separation from Christ. In a future day, when we are in the Lord’s presence, we will know true joy in the Kingdom, and then all fasting will cease.

Finally, in Acts 13 we see the apostles fasting and praying before making an important decision to anoint two new leaders in the church. As we consider any course of action, our own selfish thoughts and desires will compete for our attention with the Lord’s counsel through the Holy Spirit and His word. Our fleshly "counselors" operate out of fleshly desires, like pride, lust and greed, but the Lord’s counsel comes from the Spirit. Our fleshly voices will always oppose the counsel of the Lord. 

Therefore, we must find ways to silence our fleshly voices so we can hear clearly from the Holy Spirit. Through a discipline of regular fasting, we become practiced at quieting the flesh and amplifying the Spirit’s voice, leading to better understanding of the Lord’s will in our life.

In summary, the Bible gives us numerous, compelling reasons to engage in regular fasting as part of healthy Christian discipline.