Matthew 6:16-18 And when you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. 17 But when you fast, anoint your head and wash your face, 18 that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.
By commending secret fasting, does Jesus therefore condemn all forms of public fasting? Is our current season of fasting and prayer therefore disobedience to Christ's teaching?
I do not believe that the point of Jesus' teaching on fasting in Matthew 6 is to condemn public fasting, but rather prideful fasting. Notice that He also commends secret prayer (Matthew 6:5-6), but we do not (and should not) take that as a prohibition against public prayer in general. In fact, Jesus prays in public (John 11:41-42), the apostles followed that example (Acts 20:36), and the Scripture regulates public prayer as part of an orderly worship gathering (1 Corinthians 14:15-17). Clearly a call toward closet prayer is not a prohibition of all corporate prayer. In the same way, a call to closet fasting should not be viewed as a prohibition of corporate fasting.
In Matthew 6, Jesus is teaching about actions to expose motivations. In introducing this section of the Sermon on the Mount, He states, "Beware of practicing your righteousness before other people in order to be seen by them, for then you will have no reward from your Father who is in heaven" (vs. 1). I want to highlight in particular the phrase "in order to." If the motivation of a public action (whether giving, praying, fasting, et al) is to be seen or praised by others, then Christ certainly condemns such action, flowing as it does from a sinful desire. Christians are not to give, pray, or fast so that they might be seen. The point of the passage is the motivation of the heart. So, the question is, why are you fasting?
There is a danger in corporate fasting, just as there is in corporate prayer, that our desires will begin to turn inward and we should be quick to repent if that occurs. As verse 1 states, we should "beware" of this possibility. But the possibility of pride as the motive for public fasting does not demand that all public fasting be discontinued.
So, if you are fasting this Wednesday and some co-workers invite you to lunch, you don't have to ignore them, lie by saying "I'm not hungry," or make up some other excuse. If they press you for an explanation, it's OK to tell them that you are fasting. If in doing so you feel some pride creep in, confess it and ask the Lord to put it to death. Beware of fasting to be seen, but don't worry if you happen to be seen while fasting.