Then the disciples of John came to him, saying, “Why do we and the Pharisees fast often, but your disciples do not fast?” And Jesus said to them, “The wedding guests cannot mourn as long as the bridegroom is with them, can they? The days will come when the bridegroom is taken away from them, and then they will fast.
Fasting is one of the three things Christians are required to do during Lent, the other two being prayer and almsgiving. But why fast? There are quite literally dozens of reasons why fasting is a good idea, from better health resulting by the detoxification of the body and the rest the stomach obtains to spiritual strength one gains by resisting the demands of hunger.
Let us reflect upon the spiritual reasons, but first let us define fasting in the Christian context. It is a temporary renunciation of something that is intrinsically good — like food, in order to intensify our expression of need for something greater — which is God, and his work in our lives. This voluntary renunciation of something that is good, also helps to build our spiritual muscles, because if we can say no to what is good, then it becomes easier to say to no to what is bad.
But there are other reasons, and we find Scripture replete with them. The primary reason is repentance. After prolonged periods of rebellion, God’s people come to their senses and turn towards God. To give you one example, in the time of Nehemiah “the Israelites gathered together, fasting and wearing sackcloth and putting dust on their heads” (Nehemiah 9:1b). We don’t need to fast to earn God’s forgiveness but as a sign of genuine contrition.
Fasting also gives voice to mourning or grieving calamitous situations. In the book of Esther, when the courtier Hanan plotted to destroy the Jews, “there was great mourning among the Jews, with fasting, weeping and wailing. Many lay in sackcloth and ashes” (Esther 4:3). When we fast, we make a display of faith in God in the midst of tragedies, that he will take us through them.
A third reason is to seek God’s favor. The prophet Ezra proclaimed a fast, so that they would have a safe journey on their return to Jerusalem from exile (see Ezra 8:21). For missionaries, this favor is very important, which is why, one day, while the apostles were worshiping the Lord and fasting, the Holy Spirit told them to set apart Barnabas and Saul for missionary work. “So after they had fasted and prayed, they placed their hands on them and sent them off” (see Acts 13:2-3).
A final reason, although there are plenty more, is that when we fast we declare to God: I need you more than anything else Lord, even food!