In one of the earliest Christian writings outside of the Bible, we read that the first Christians regularly fasted twice a week (Didache, 8).  For many modern Christians, however, fasting is not a spiritual tool regularly handled.  Some will attempt some kind of fast during Lent; some never at all.

That leaves us with basic questions about what fasting is for and how to practice it.  The Bible does not obviously answer those questions because the first-century audience included many people who assumed basic practices of fasting.  When Jesus teaches in the Sermon on the Mount, He also assumes fasting, saying, “When you fast…” (Matthew 6:16).

Looking through the Old Testament, we can see different kinds of fasting.  Individuals fast when they are grieving (2 Samuel 1:12; 3:35) and when they are seeking the Lord (Esther 4:15-16; Daniel 9:3).  Communities fast in repentance (Judges 20:26; Jeremiah 36:9; Jonah 3:5) and in solemn preparation to receive atonement (Leviticus 16:19-21).  In the New Testament, the church fasts before the start of ministry (Acts 13:2; 14:23).

There are also notable moments where fasting is expected but doesn’t happen.  In Matthew 9:14-17, the disciples of John ask Jesus why they and the Pharisees fast but Jesus and His disciples do not.  Jesus answers that His disciples will fast, but not as long as the bridegroom is among them.  In that exchange, Jesus connects fasting with mourning (9:15).  David is also considered remarkable since he did not fast for his child who died (2 Samuel 12:16-23).  David indicates that he mourned and sought the life of the child while he was alive, but that once the child had passed, the child was with the Lord (12:23).

These instances of not-fasting help us see what fasting is for.  Fasting is a physical expression of mournfulness, recognizing our absence from God.  This is why it is anathema for Jesus to see a person who fasts become proud while fasting (Matthew 6:16-18; Luke 18:12-14).  You are doing fasting wrong if you are pleased with yourself for what you are doing.

The right spirit of fasting is expressed by the Canaanite woman (Matthew 15:21-28).  When she does not hear an answer from God, she persists in prayer.  She does not look for the full meal, for even the crumbs of the Lord’s table will satisfy her.  The person who fasts is trying to decrease the satisfaction taken in the lesser good (usually food), in order to heighten appreciation of the greater good of God’s gracious presence.

Looking back, then, to the kinds of fasting we considered in the Bible, we can make better sense of them.  Fasts for public grieving or public repentance invite the community to join in the grief of the shared loss or shared sin.  These fasts cannot be hidden fasts, as Jesus enjoins in Matthew 6:16-18, because there is little temptation to individual pride.  Furthermore, there is love to be shared if the community bonds through a shared fast.  It is the private fast done individually for self-discipline that Jesus insists be done like almsgiving and prayer, without any attention drawn to the self.

Luke 18:12-14 describes a man who does all those good deeds- praying, fasting, and giving away his property- but not being justified by what he does.  He is left to his pride because his acts are self-worship.  Jesus explains how this works (or doesn’t work) in Luke 7:36-50.  The man who thinks he has little to be forgiven for loves little, but the “sinful woman” who grieves her sin becomes full of love when she is forgiven much.  Christian fasting, therefore, will uncover our need for forgiveness, preparing the ground for rich seeds of Gospel love.  Unchristian fasting hides the need for forgiveness by imagining how much better the life is directly because of the fast (or almsgiving or prayer).

Therefore, it is dangerous in fasting to give up something you think you maybe need to be giving up anyway.  The New Testament makes it clear that there is no holiness to be found in a particular diet.  “Food will not commend us to God.  We are no worse off if we do not eat, and no better off if we do” (1 Corinthians 8:8).  “Do you not see that whatever goes into a person from outside cannot defile him, since it enters not his heart but his stomach and is expelled” (Mark 7:19).  If, instead of following Jesus and Paul, you try to combine a fast and a diet because you need to lose some weight, too, the spiritual self-discipline gets lost in the earthly gains.  It is hard to suppress pride when you are feeling healthier.

In the first century, remember, food was not primarily seen in the prism of health concerns we have today.  Food was not just for nourishment, but also for fellowship (Luke 15:2) and celebration (Luke 22:15-16).  Withdrawal from food was not only seen as physically debilitating (Matthew 4:2) but also lonely (John 4:31-32).  The choice not to eat was clearly one in which you temporarily gave up an agreed upon good thing in order to get a more secure hold on the only eternal good.

This is why discussion of fasting needs to also discuss the breaking of the fast.  When you return to the minor good once more, it is a Gospel moment, a celebration of God’s gracious giving.  Consider the fast Paul describes in 1 Corinthians 7:5.  Husband and wife fast sexually in order to devote themselves to prayer, but their return to one another is assumed.  When David breaks his fast, his actions also are focused on sharing comfort as God’s gift (2 Samuel 12:24).

The pattern of fasting, therefore, is separation from an earthly good to give mournful focus, disciplining our pride.  Then, when this is accomplished, we come back to God, receiving His gifts with joy and thanksgiving.  This is the rationale of another ancient Christian practice, to fast before receiving the Eucharist, breaking your fast with the Bread of Life.

There may be other earthly fasts we attempt to control our earthly lives.  Before a surgery, we stop eating.  If we find smartphones taking over our lives, we force ourselves to power down.  If sports or news are enraging us, we go take a walk.  If clutter closes in, we konmari away.  If acid reflux is churning, we limit ourselves to one deep fried twinkie a day.  These things can all make us healthier in this life.  But food will not commend us to God, and neither will landline phones, cable cord cutting, and emptied closets.  Indeed, you can praise God, thanking him for the opportunity to launch an angry bird, to cheer a touchdown, and even to take a bite of deep fried goo.  “For everything created by God is good, and nothing is to be rejected if it is received with thanksgiving, for it is made holy by the word of God and prayer” (1 Timothy 4:4-5).  That is the ironic goal of fasting, to come back to His creation in thanksgiving.