One of the greatly neglected means of grace in the contemporary church is fasting. Yet God teaches us to fast. In 1 Samuel 7:6, the people fasted in connection with repentance of sin; in 2 Chronicles 20:3, Jehoshaphat called a fast to seek the Lord's favor and deliverance.
But fasting is not merely an Old Testament phenomenon. It is clearly taught in the New Testament as well. Although it was unique, the fast of Jesus in Matthew 4:1, 2 shows us its importance. In Matthew 9:15, Jesus points out that fasting was for times of mourning and seeking, and not for the time of joy. "But the days will come when the bridegroom is taken away from them and then they will fast." Jesus assumed that we would fast. In Matthew 6, He calls fasting a deed of righteousness and puts it into the category with giving money to the poor and prayer. Since it is clearly established in the Old Testament, He saw no need to re-issue a command. He simply assumed that true believers would fast (Matthew 6:16), "And when you fast..."
Moreover, not only was fasting practiced and demanded by Jesus, it was also practiced by the New Testament church. In Acts 13:3, when the church ordained Saul (Paul) and Barnabas, we read: "Then when they had fasted and prayed and laid hands on them, they sent them away." Paul and Barnabas observed the same practice in Acts 14:23:
And when they had appointed elders for them in every church, having prayed with fasting, they commended them to the Lord in whom they believed.
In light of the above verses, it is evident that fasting, when it is coupled with prayer, is a divinely appointed means of grace to be practiced by Christians. But what about public fasting? After all, doesn't Jesus say not to fast to be seen by men? In order to answer this question we must compare Scripture with Scripture. There are certainly examples of private fasting such as we find in Nehemiah 1:4: "Now it came about when I heard those words, I sat down and wept and mourned for days and I was fasting and praying before the God of heaven." But there are also examples of public fasts. We have already noted the practice of the Church of Antioch in Acts 13. Another example is seen in 2 Chronicles 20:3, 4 in the fast called by Jehoshaphat who "proclaimed a fast throughout all Judah to seek the Lord." Here we have a clear example of God's people meeting together in a public fast in order to seek the Lord.
How then do we reconcile this with Jesus' command that we should not fast in order to be seen of men? The answer is quite simple. Jesus is no more prohibiting public fasting than He is prohibiting public prayer when He says that we are not to do these things to be seen of men. He is not dealing with the practices of fasting or prayer but with the motives. We are never to do these things to be praised by men. We are only to do them to seek the Lord. Our motive must always be God-centered and never man-centered.
Having established a biblical basis for private and public fasting, let us look now at the purpose of fasting. We will not attempt to cover all the purposes, but just the two general purposes: one negative and one positive.
The positive purpose is to seek the Lord. Fasting is an aid in prayer and meditation. This was the reason for Jehoshaphat's fast in 2 Chronicles 23: "Jehoshaphat was afraid and turned his attention to seek the Lord and proclaimed a fast throughout all Judah."
As Calvin says, "Their sole purpose in this kind of fasting is to render themselves more eager and unencumbered for prayer. Surely we experience this: with a full stomach, our mind is not so lifted up to God that it can be drawn to prayer with a serious and ardent affection and persevere in it."Institutes, Vol. IV, Ch. 12, Sec. 16
Fasting coupled with prayer for a specific purpose gives intensity to the prayer. The mind is keen and sharp as the body joins with the soul in pleading with God.
The negative purpose is to be a testimony of our self-abasement before God when we wish to confess guilt before Him. We see a clear example of this in Joel 2:12-16:
Yet even now, declares the Lord, return to me with all your heart, all with fasting, weeping and mourning; and rend your heart but not your garments. Now return to the Lord your God, for He is gracious and compassionate, slow to anger abounding in loving kindness, and relenting of evil. Who knows whether He will not turn and relent, and leave a blessing behind Him, even a grain offering and a libation for the Lord your God? Blow a trumpet in Zion, consecrate a fast, proclaim a solemn assembly, gather the people, sanctify the congregation, assemble the elders, gather the children and the nursing infants...
On this passage Calvin comments, "He cries out for them to hasten to sackcloth and ashes, to weeping and fasting, that is, to prostrate themselves before the Lord also with outward testimonies. Indeed, sackcloth and ashes were perhaps more appropriate to those times; but there is no doubt that meeting and weeping and fasting, and like activities, apply equally to our age whenever the condition of our affairs so demands. For since this is a holy exercise both for the humbling of men and of their confession of humility, why should we use it less than the ancients did in similar need?... No, it is an excellent aid for believers today (as it always was) and a profitable admonition to arouse them in order that they may not provoke God more and more by their excessive confidence and negligence..."Vol. IV, Ch. 12, Sec. 17
We see here that it is a means of humbling ourselves before God in order to express our true sorrow and repentance.
Therefore we ought to fast both privately and publicly when public fasts are called by synod or the consistory. Great spiritual benefits are connected to this exercise. If you are neglecting fasting, you are missing out on one of the things that God has appointed for your sanctification. It is true that some, because of health, will not be able to abstain totally, but all can deprive themselves to some extent for the purposes we've discussed. Those who do not totally abstain "should eat more sparingly and lightly than is their custom" (Calvin's Institutes Vol. IV, Ch. 12, Sec. 18).