The Truth About Fasting

Fasting has ordinarily been practiced as giving up food for a fixed time, and has been a fixture of the Christian tradition since its beginnings. One of the earliest Christian documents, the Didache, has several instructions regarding fasting that touch multiple aspects of life, which indicates that fasting’s importance was suffused throughout early piety. Drawing on Jesus’ words recorded in Matthew 5:44 and Luke 6:28, the Didache exhorts Christians to bless those who curse us, pray for our enemies, and fast for our persecutors (1:7). It further instructs new converts to fast in preparation for baptism (7:6–7). Lastly, and perhaps most broadly, it again joined fasting to a believer’s prayer life, and advised that Christians should fast on the fourth day of the week and the sixth in preparation for the Lord’s Day instead of on days that “the hypocrites” (i.e. the Pharisees) fast (8:1–2).[1] These points from the Didache tell us that early Christians incorporated fasting into major parts of life, and took the practice seriously. The questions that rise from this ancient practice, and the topics addressed in this article, are why they would so devotedly observe it, whether it continued on through the ages of the church, and what that should tell us about how we should think about fasting.
The main reason why the early church fasted was because it is taught in Scripture and was passed down to them from Judaism, Jesus’ teachings, and the apostolic practice. Scripture records that God’s people fasted in conjunction with major events or when they were fervently seeking God in desperate times. In Exodus 34, when God gave the second set of tablets detailing the law, Moses was with God and fasted from bread and water for forty days and nights. In 1 Samuel 7, when Israel turned back to God in light of an impending Philistine attack, the nation fasted and confessed their sin to God. In 2 Samuel 1, as David and his men grieved Saul’s death, they fasted in mourning. In Ezra 8:21–23, the Israelites who would return from exile to the Promised Land fasted to seek the Lord in intense prayer for protection on their journey. In Nehemiah 1, the news that Jerusalem’s fortifications were destroyed provoked Nehemiah to prolonged fasting and prayer as he sought repentance among his people and their restoration before God. In Nehemiah 9, the people included fasting as a sign of their mourning as they repented of their sins. Clearly, Scripture records how people fasted to seek God in an intense way, most often conjoined with prolonged prayer, and that fasting was, far from being a mark of empty outward practice, supposed to mark true mourning over loss, true repentance over sin, or true humility in seeking God (Ps. 69:9–12; Is. 58:1–14; Jer. 36:1–9; Jl. 1:13–16; Jl. 2:12–16).

The New Testament also enjoined the same kind of sincere fasting, not for appearances, but for seeking God. In Matthew 6:16–18, Jesus warned his followers to avoid fasting like hypocrites, who do so in order to be seen. In Mark 2:18–22, he explained that his disciples did not fast while he was with them because fasting is for a time of mourning when their bridegroom is not with them. Fasting is often joined with worship and prayer (Lk. 2:37; Acts 13:2–3; 14:23).[2] The New Testament view on fasting, therefore, stands in continuity with the Old Testament by endorsing fasting as a way to repent of sin, mourn over loss, or intensely seek God in prayer and worship.

Interestingly, the Scripture never demands that Christians fast, which raises the obvious question about its continuation. The Scripture does speak positively of fasting, and Jesus’ language of “when you fast” assumes that his followers would be doing it. In a complementary way to how the Scripture commends fasting, church history exhorts Christians to fast. Justin Martyr (c.100–165), one of the first Christian apologists, picked up the instruction of the Didache for new converts to seek God in fasting before being baptized.[3] Tertullian (c.160–225) also advocated for pre-baptismal fasting, but further wrote an entire treatise on fasting.[4] In On Fasting, he argued that gluttony and the love of food are tied to the fleshly nature that came about after Adam’s Fall.[5] He strongly set physical against the spiritual strength, arguing that intense fasting and specific dietary restrictions were for a person’s spiritual good. Read more»

Harrison Perkins | “Fasting and the Pursuit of God” | March 11, 2020


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  1. The book of Esther mentions fasting without mentioning prayer – but isn’t that because mention of God and mention of prayer are both excluded from the book in order to preserve the typology of the court of the King of Persia being a type of heaven (and Mordecai being a type of Christ)?

    Wasn’t the Didache, which preaches Justification by Works (4:6), merely a Montanist document (along with the Epistle of Barnabas)?

    • The Didache predates Montanism. Whether it teaches justification by works depends on its context. It seems concerned with ethics and church order, not really touching on justification. I understand the way leading to life as what a Christian life should look like, not how we are saved.

    • John, your question could also be applied to James 2:17 and 26. In much the same way as James, the Apostles in Didache 4:6 are making the point that our giving is to be an act of faith, and as such, a ransom for our sins. James’ point is that believing and doing are two sides of the same coin. In Didache 2:5, the Apostles teach “do not let your words be false of empty, but be fulfilled by action.” So for both James and in the teaching of the Apostles in the Didache, works are evidence of faith, not the basis of justification. Works, including giving by faith, are the natural outflow, or fruit, of our gift of faith. Where there is no fruit, one’s faith is dead; living faith bears fruit.

      • James says indeed that the works of faith justify. But nowhere does he imply that works of faith, or faith itself are in any way a ransom for sins. Any document that says that, e.g., the Didache or the Epistle of Barnabas needs to be dismissed forthwith as worthless or even worse. Didache 4:6 and the parallel verse in the Epistle of Barnabas say exactly that.
        There is only one ransom for sins, and it is neither our works nor our faith.

        • John,

          James does NOT teach that our works justify us before God but rather he says that our good works vindicate or give evidence of one’s claim to be a believer.

          Didache 4.6 says, “ ἐὰν ἔχῃς διὰ τῶν χειρῶν σου, δώσεις λύτρωσιν ἁμαρτιῶν σου.”

          This is at worst a heavy-handed figure of speech and cryptic.

          Your interpretation is not necessary.

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