Biblical fasting is a sacrificial, voluntary abstaining from food for a definite period of time for a spiritual purpose.

Biblical reasons to fast

There is a sense in which Jesus’ own example of fasting and His assumptions about the lives of His followers ought to be reason enough for us to give ourselves to this practice. But God, in His great mercy, has provided many additional reasons in the Bible for us to embrace the practice of fasting as Christians. Here are six of them...

• To show our earnestness: Fasting helps us express an earnestness in our prayers (Acts 14:23). In denying ourselves food, we are telling the Lord that we mean business, that we are putting our money where our mouth is, so to speak. Andrew Murray put it this way: “Fasting helps us to express, to deepen, and to confirm the resolution that we are ready to sacrifice anything, to sacrifice ourselves, to attain what we seek for the kingdom of God.”
• To express our wholehearted faith in seeking the Lord: Oftentimes in the Bible, fasting is an expression of wholehearted devotion to God. It is a way of showing that we really are repentant and that He really is more important to us than mere physical pleasures (Joel 2:12–13).
• To plead with the Lord: At other times, fasting is an expression of mourning—either over death (2 Sam. 12:16) or over sin (Jonah 3:5)—and of pleading with the Lord to hear our prayers for mercy and for healing. That would seem to be the point of Jonah 3:5; Esther 9:31; and Joel 1:14.
• To seek wisdom and guidance: In 2 Chronicles 20:1–30, Jehoshaphat proclaimed a national fast in order that all the people might seek the Lord’s wisdom and guidance in the midst of an encroaching military horde that was coming on them from Edom. This suggests that fasting and praying in the midst of daunting tasks and overwhelming circumstances are entirely appropriate for us.
• To express humble reliance on the Lord: In Ezra 8:21–23, we have evidence of a fast being proclaimed as an expression of humility and dependence on God for His provision. Here, fasting is not entered into lightly or flippantly but with humble reliance on God that He will hear their prayers and provide what they need when they need it.
• To prepare ourselves against temptation: In Matthew 4:1–3, Jesus fasts so that He might be able to withstand the devil’s temptations, not in order that the devil might have grounds on which to be able to tempt Him, as some may think. (Satan tempts Jesus three ways, not just in His physical appetite.) If Jesus fasted to be better prepared for temptation, how much more should we do likewise?

In all these things, we need to remember that fasting is never a way of manipulating God into answering our prayers or showing us mercy. It is not a hunger strike to ensure that God will meet our list of demands. It is a way of expressing our love for Him and our gratitude for all that He has done for us. It is a way of communing with Him and of keeping our hearts fixed upon Him. The world is continually seeking to pull our desires away from the Lord. It continually beckons us to find our pleasure in food or drink or other worldly delights. Fasting reminds us that the Lord is our chief pleasure, and it trains us to keep it that way. It helps us remember that “fullness of joy” and “pleasures forevermore” can only be found in His presence and at His right hand (Ps. 16:11). For this reason, fasting plays an important role in the battle for our desires, which lies at the heart of what Christianity is all about. We neglect it to our peril.