The very idea of fasting is foreign to the vast majority of western Christians. It ought not to be viewed as a mystical means to greater piety or a deprecated vestige of medieval traditionalism or asceticism. Fasting is a biblical practice of saints that, for various reasons, voluntarily choose to express their humble devotion to God with a particular purpose in mind.

Under the Old Covenant, the Day of Atonement was the only public day of fasting (“literally ‘you shall afflict yourselves,’ chiefly by fasting, as testified by Isaiah 58:3, 5, 10” [Jacob Milgrom, JPS Torah, 246]) prescribed by the Law (cf. Lev 16:29; 23:26-32; Num 29:7-11). Fasting always has as its highest aim, worship (cf. Luke 2:36-37). It is a peculiar expression of creaturely humility, dependence, and weakness. Moreover, it is most predominantly exercised in concert with prayer (cf. Judg 20:26–28; 2 Sam 12:16; Ezra 8:21–23; Neh 1:4-11; Est 4:3, 16; Ps 35:13; 69:10; 109:22–25; Jer 14:12; Dan 9:3; 10:2, Joel 2:12; Acts 9:8–11). It should be noted that fasting without genuine faith and repentance is meaningless (cf. Is 58:1-10; Jer 14:10-12; Lk 18:9-14). Also, fasting does not replace our God given responsibilities (cf. Zech 7:1-14).

Fasting is the act of total or partial abstinence from food for a limited period of time in express devotion to God. While the principle is most fundamentally that of self-denial, food is the most precise object of fasting in the Bible. Therefore, while we may choose to ‘fast’ from various other enjoyments in life, food has a particular attachment to the purpose of fasting. The Hebrew verb sum is the only term used to describe fasting and conveys the explicit meaning “to abstain from food” (Merrill, EDBT).

While the purpose of fasting is never explicitly stated in Scripture, there are several very plain reasons inferred and derived from the contextual situations wherein fasting is rightly performed:

1. An Act of Worship in Express Humility and Dependency — “Fasting increases our sense of humility and dependence on the Lord (for our hunger and physical weakness continually remind us how we are not really strong in ourselves but need the Lord)” (Grudem, 390).

2. A Tangible Reminder that We Are Living Sacrifices to GodJust as we temporarily sacrifice some personal comfort to live unto God, so fasting serves as a tangible reminder that we are to live as living sacrifices unto God (Rom 12:1-2).

3. Self-Discipline for Spiritual TrainingFasting is meaningless without its spiritual counterpart. It is an exercise in self-discipline, the active refrain of something we would naturally desire. In this, fasting reminds us to practice self-discipline in the face of temptation, that we might actively seek to strengthen our ability to deny temptation’s ‘hunger pain’. “If we train ourselves to accept the small ‘suffering’ of fasting willingly, we will be better able to accept other suffering for the sake of righteousness (cf. Heb. 5:8; 1 Peter 4:1–2)” (Grudem, 390).

4. An Aid for Focusing on Eternal Spiritual RealitiesFasting is also very effective to aid us in focusing on eternal spiritual realities (cf. Col 3:1-2). It heightens our spiritual and mental alertness and sensitivity to God and His purposes in our lives. Indeed, fasting aids our efforts to discipline our thought life to more consistently glorify God and therein find our deepest satisfaction.

The New Covenant does not stress fasting, nor does it lay down any regulations concerning its observance. However, Jesus clearly implies that His disciples will fast when He says, “And when you fast” (Matt 6:16). It is interesting that when asked why His disciples did not fast according to the customs of the Pharisees during His ministry, Christ responded, “Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away from them, and then they will fast” (Mt 9:15). The time when the disciples of Jesus fasted, was to come with His departure.

Christians exercised fasting corporately and personally when facing substantial decisions (cf. Acts 13:3; 14:23) and entreating the Lord’s will in general (cf. Acts 9:8-9). History reports to us that from the second century on, the church devoted times of fasting in preparation for Good Friday and Resurrection Day.

In light of our study in John and particularly are recent meditation on the primacy of God’s glory (John 11:1-16), let us entreat the Lord, in unusual manner, to work in us a deeper understanding of our purpose in life to glorify Him. Let us wisely consider how we might fast and pray, especially this Good Friday, for the purpose of confessing our sins and earnestly seeking a renewed sense of grace in Christ. May we earnestly pray and seek the face of God, considering how we might more consciously pursue, see, and appreciate His glory in the circumstances of our lives.

Richard Baxter commended the church to fast and pray on special occasions, whether for thanksgiving, or on occasion of great sin and lack of devotion to God. He wrote:

It is meet that in public, by fasting and prayer, we humble ourselves before the Lord, for the averting of his displeasure; and on such occasions it is the pastor’s duty to confess his own, and the people’s sins, with penitence, and tenderness of heart, and by his doctrine and exhortation, to endeavour effectually to bring the people to the sight and sense of their sin, and the deserts of it, and to a firm resolution of better obedience for the time to come, being importunate with God in prayer for pardon and renewed grace.
—Richard Baxter, The Practical Works of the Rev. Richard Baxter: Volume XV (London: James Duncan, 1830), 498-99.