In the Sermon on the Mount, Jesus drives home the importance of normal, regular fasting for His disciples with a warning, a command, and a promise, "And whenever you fast, do not put on a gloomy face as the hypocrites do, for they neglect their appearance in order to be seen fasting by men. Truly I say to you, they have their reward in full. But you, when you fast, anoint your head, and wash your face so that you may not be seen fasting by men, but by your Father who is in secret; and your Father who sees in secret, will repay you" (Matthew 6:16-18).
First, notice that fasting is not an exercise of ritual correctness: for those who must put on holier-than-thou airs. Jesus says that when we fast, we are not to look like it. None of that baptized-in-vinegar look. No woe-is-me-I'm-in-the-midst-of-a-spiritual-trial expression to wrinkle our nose or mar our visage. Fasting is supposed to evoke humility. If we fast for some outward, physiological, or social benefit; if we fast for whatever sympathy, empathy, or kudos we can muster, then we have already received our reward in full. "Do not put on a gloomy face as the hypocrites do," that is the warning.
Second, fasting is to be a part of our regular routine. It is to be seamlessly woven into our normal lifestyles. It is to be fully integrated into our walk with both God and man--with a minimum of disruption. We're to do good--but we're to look good while doing it. "Anoint your head, and wash your face," that is the command.
Third, fasting is Godward in its orientation. It's only audience is Him. It's only intent is Him. It's only object is Him. It is wholly and completely subsumed in Him. "And your Father who sees in secret, will repay you," that is the promise.
Inherent in all three--the warning, the command, and the promise--is the assumption that no matter what, one way or another, the disciples will fast. That much is understood. It is assumed. It is a given. "When you fast," Jesus says (vs. 16). And again He says, "when you fast" (vs. 17). No ifs, ands, or buts about it. "When."
Our fasting may be absolute (Deuteronomy 9:9) or partial (Daniel 10:3). It may be entirely private (Nehemiah 2:1) or demonstrably corporate (Jeremiah 36:6). It may be occasional (Acts 13:3) or seasonal (Zechariah 9:19). But one thing is certain: if we are followers of Christ; if we are genuine Christian disciples; if we are seriously seeking the will of God, obeying His Word, and walking in dependence on Him, we will fast (Matthew 9:14-15).
It is interesting to consider that Adam and Eve lost both their spiritual purity and their temporal paradise--all because they failed to fast at the appropriate time.
It is equally interesting to survey the annals of history to discover that virtually all of the heroes of the faith through the ages have put a high priority on fasting. From Athanasius to Augustine, from Polycarp to Patrick, from John Chrysostom to John Calvin, from Brother Andrew to Mother Teresa, and from Francis of Assisi to Francis Schaeffer, the saints of yore took advantage of every appointment of grace--not the least of which was fasting. Not only that, but they encouraged their churches, their communities, and their nations to do likewise. It is nothing if not common to find references to whole congregations consecrating themselves to covenantal fasts and solemn assemblies. Calls by national leaders for days of prayer and fasting were regular occurrences throughout the West during the glory days of Christendom. Washington, Adams, Jackson, Lee, Davis, Harding, Coolidge, and Eisenhower all stood foursquare in that tradition of "seeking first the kingdom" by establishing regular days of national repentance and fasting.
It would have been inconceivable to any of them to neglect such an essential aspect of humble discipleship--as inconceivable as substituting recovery for repentance, serenity for sanctification, or limericks for creeds.
Otto Blumhardt, the great seventeenth century Lutheran missionary speculated that should the day ever come when such substitutions did actually occur, the minions of the "culture war" would be the least of our worries. He said, "On the day the church abandons its care of the poor, its fervent ministry of supplication, and its intently chosen fast--for whatever good will or intentions--on that day we will undoubtedly see its clergy dragged off in wickedness and promiscuity, its parishes awhoring after greed and avarice, and its congregations awash in every vain imagination and unspeakable perversion. On that day, the church will cease to be the church. May it never be. May it never be. Stay that day with the hand of faithful diligence, I pray. Stay that day with the fastening of faith."