As he did with almsgiving and prayer, Jesus redefines fasting as a private act of worship. Jesus assumes his disciples will fast since he says “when you fast.” But the true disciple of Jesus will practice fasting in a way which does not draw attention to themselves. Quite a few years ago I had a friend start a ten-day fast. I remember this because he reminded every day (sometimes several times a day) that he was fasting. It is like the old joke, how do you know someone is a Vegan? Talk to them for five minutes.
When the hypocrites fast, everyone knows what they are doing. The hypocrites “destroy (ἀφανίζω) their faces, a verb which means to render something unrecognizable, even “wear a disguise.” The Pharisees “seem to don masks during their fasting” (BDAG). Perhaps they wore older clothes or even sackcloth to appear to be in great distress after a long fast. The hypocrite wants people to know they are fasting so they are thought to be especially spiritual. Just like the one who makes a demonstration of almsgiving or public prayers, everyone knows the person is fasting.
Unlike the hypocrites, Jesus tells his disciples not to look like you are fasting. Jesus says his disciples should not “look somber” of “gloomy” (σκυθρωπός). The only other place this word appears in the New Testament is Luke 24:17, the two disciples on the road to Emmaus looked gloomy after the crucifixion. In LXX Psalm 37:7 (ET 38:6) the verb describes a person who is in mourning.
The person who is fasting should would wash daily, but the hypocritical person might not wash at all in order to appear in more distress. Jesus says, “Clean yourself up and look normal” when you fast. More than looking normal, Jesus seems to advise appearing to be “not in mourning.” Anointing one’s head was done as a sign of joy (Ps 23:4), perhaps more than daily personal cleanliness (it is more special than “use shampoo and conditioner).
Is there really spiritual benefit to fasting? Augustine said “Do you wish your prayer to fly toward God? Give it two wings: fasting and almsgiving.” (Cited by Wimmer, Fasting in the New Testament, p. 114)
As should be clear from the overview of biblical fasting, the practice does have a place in the Christian life as a spiritual discipline.
One important observation about Jesus’s teaching on fasting is that did not cite any examples of people who have fasted in the Old Testament, Moses or Elijah, nor did he put his own experience forward as a model of how to fast. Although there are people who have completed forty day fasts, this is not the normal practice in the ancient world and it is never presented as a model for modern Christians.
It is not the case that a longer fast is “more spiritual” than a short fast, or that a total fast is better than a fast during the day with a small meal in the evening. Like communion, whatever you do, do it to the glory of God.
McKnight offers two very important warnings about fasting. First, churches should be very careful about how the present fasting because eating disorders are dangerous and some people may be negatively impacted by a period of fasting. Second, fasting is not abstaining from some particular activity (such as giving something up for Lent). Even though people go on an “internet fast” or a “TV fast,” this is not at all what the Bible is talking about (McKnight, Sermon, 202).
As Jesus commanded, fasting should be a private practice as much as possible. It is possible for a faith community to use prayer and fasting when coming to an important decision. Like Paul and Barnabas, perhaps a day of fasting and prayer can be used for appointing leaders or commissioning people to ministry.
In addition, churches could consider a day of fasting in response to a terrible event in the life of the community, or even in the life of the nation. McKnight suggest a time of prayer and fasting in response to a natural disaster or terrorist attack. The point would not be an attempt to manipulate God into action, but to focus the attention on God in response to the disaster.
But if someone decides to go through a period of fasting, they last thing they ought to do is announce it for all to hear, or sigh loudly when they are hungry, or go out to lunch and not eat in order to make every one aware of their spiritual discipline.
Those who fast ought to focus on their response to God, not in order to create a spiritual experience. This is not biblical, even though fasting can put one in a psychological place to have a spiritual experience.
I would love to hear from some readers on their own experience with fasting as a spiritual discipline. How does a private fast differ from a public demonstration? How does fasting focus one’s spiritual thinking?