And whenever you fast, do not look dismal, like the hypocrites, for they disfigure their faces so as to show others that they are fasting. Truly I tell you, they have received their reward. But when you fast, put oil on your head and wash your face, so that your fasting may be seen not by others but by your Father who is in secret; and your Father who sees in secret will reward you.
Jewish people, during the time of Jesus, fasted privately during times of mourning, when making amends for sins, when preparing for major events in their lives, when struggling with decisions, to seek deliverance and protection, to express repentance, to overcome temptation, and during times of urgent physical or spiritual needs.
A fast often lasted from sunrise until sunset, (2 Samuel 1:12) and it could be a total or partial abstinence from food (Psalm 35:13). The objective of the fast was to focus a person's attention on God, to humble oneself before God, and to emphasize a person's total dependence on God.
There was only one day, the Day of Atonement (Yom Kippur), on which public fasting was required. On that day, the High Priest performed elaborate rituals to atone for the sins of the people. The Pharisees, however, took fasting to new heights and fasted regularly on the second and fifth day of every week, much of which was done in public so that their piety could be observed for all to see.
In the verses above, Christ describes the lengths that the Pharisees went to be seen as pious. They put on an expression of suffering, they covered their faces with ashes and dust, they disheveled their hair, they dirtied their clothes and they walked through the streets for everyone to witness their suffering.
There is no religious value in practicing a spiritual discipline, such as fasting, for its own sake (mechanically or routinely with no passion or emotion) or as a demonstration of piety, or for any other ulterior motive (such as losing weight). Once the focus shifts from God to the person practicing the discipline, it becomes wrong.
When we fast or, for that matter, make any kind of self-sacrifice that is for spiritual reasons, Christ says that we should go about our public lives as normal so that our sacrifice is seen only between us and God.
Tomorrow we study eternal treasures.