“Moreover, when you fast, do not be like the hypocrites, with a sad countenance. For they disfigure their faces that they may appear to men to be fasting. Assuredly, I say to you, they have their reward. But you, when you fast, anoint your head and wash your face, so that you do not appear to men to be fasting, but to your Father who is in the secret place; and your Father who sees in secret will reward you openly.”
Like anything, the spiritual tool of fasting can be misused. The proper use of fasting will humble us (Psalm 35:13), but Jesus Christ warned us against using fasting to feed our pride—to make other people think more highly of us. “Wow, he’s fasting again—he must be very righteous and close to God!” is the kind of reaction these hypocrites wanted.
But Jesus taught that fasting is a personal tool for spiritual growth. Though there are occasions like the Day of Atonement when the Church of God, a Worldwide Association, fasts as a community, most fasting is private and in that sense “secret” from the outside world.
One commentator wrote, “The inner life must always be a denial of self, but we must come to the world with a smile and a song, and the anointed head, and the washed face” (G. Campbell Morgan, The Gospel According to Matthew). To be a Christian is to humbly choose to give to others as Christ gave, not to try to manipulate them to get honor for ourselves.
For more about avoiding hypocrisy, see “The Pharisee and the Tax Collector.”