What would be an appropriate framework for me to understand fasting?
Fasting (Heb. tzom; Grk. nēsteia) is something which is practiced in many religions the world over, as deprivation of food and/or water is believed to stimulate other human senses, and consequently focus the attention of a person onto spiritual matters. Fasting is witnessed in both the Tanach and Apostolic Scriptures, for a variety of important reasons. Among the notable days of fasting in the Holy Scriptures is Yom Kippur or the Day of Atonement (Leviticus 16:29-31; 23:26-32; Numbers 29:7-11; cf. b.Yoma 11a; 73b), actually specified in Acts 27:9 to be “the fast.” Some of major reasons for fasting in the Bible, are summarized by what is witnessed in Isaiah 58:6-7:
“Is this not the fast which I choose, to loosen the bonds of wickedness, to undo the bands of the yoke, and to let the oppressed go free and break every yoke? Is it not to divide your bread with the hungry and bring the homeless poor into the house; when you see the naked, to cover him; and not to hide yourself from your own flesh?” (NASU).
Noting the importance of this passage, The Oxford Dictionary of the Jewish Religion details,
“Physical abstention is regarded not as an end in itself but as a means to spiritual affliction and self-abasement. This finds eloquent expression in the portrayal of the true fast in Isaiah 58, which was adopted not only as the prophetic reading for Yom Kippur but was probably read on the occasion of each public fast.”
Within Judaism, the Ninth of Av, a day which commemorates the destruction of the First and Second Temples, is also observed as a traditional fast. Zechariah 8:19 also specifies how “The fast of the fourth, the fast of the fifth, the fast of the seventh and the fast of the tenth months will become joy, gladness, and cheerful feasts for the house of Judah; so love truth and peace” (NASU).
While there are designated times of fasting in the Bible, as well as traditional times of fasting within Judaism, many individuals themselves will be convicted, or will choose to abstain from food and/or water for particular seasons—usually to press in to God, and to seek answers or resolution to an issue from Him. The following is a list of some of the notable places where fasting appears in the Bible:
- times of national crisis for Ancient Israel (Joshua 7:5-13)
- tribal war against Benjamin (Judges 20:23-26)
- fasting by the Israelites when the Ark of the Covenant was restored by the Philistines (1 Samuel 7:6)
- fasting by Nehemiah when hearing about the condition of Jerusalem (Nehemiah 1:4)
- Joel summoning the people to return to God (Joel 2:12)
- Esther calls her fellow Jews to plead for their people (Esther 4:16-17)
- fasting by Cornelius when being told to send for Peter (Acts 10:30)
- fasting on behalf of Paul and Barnabas, and their first missionary journey (Acts 13:3)
- Paul’s advice for likely fasting various periods of time during a marriage relationship (1 Corinthians 7:5)
- the fasting of Yeshua for forty days in the wilderness (Matthew 4:2)
It is not at all surprising to see that Yeshua the Messiah Himself gave some instructions regarding fasting. While fasting was to be a spiritual discipline commended, there would be those who would draw others’ attention to their fasting in an effort to be spiritually arrogant. Yeshua directed,
“But you, when you fast, anoint your head and wash your face so that your fasting will not be noticed by men, but by your Father who is in secret; and your Father who sees what is done in secret will reward you” (Matthew 6:17-18, NASU).
Fasting often involves self-humiliation and repentance (1 Kings 12:27; Psalm 35:13), prayer (Matthew 17:21; Acts 13:3), and the distinct work of the Lord (Ezra 8:23). There can be abuses, however, associated with asceticism (cf. Colossians 2:18) or forms of false humility where human people intend to insist something upon an Eternal God as a result of fasting. William Kelly offers an appropriate summary of fasting in the Baker’s Dictionary of Theology:
“As with any religious practice, there are dangers in fasting which are clearly noted in Scripture. The fast may be regarded as a means of getting things from God (Isa. 58:3). It may be substituted for the genuine repentance which issues in amendment of life (Isa. 58:5ff.). It may become a mere convention and therefore an end of itself (Zech. 7:5). It may become an occasion for a parade of religion (Matt. 6:16) and thus finally lead to the self-righteousness which is the very opposite of true repentance and therefore of justification before God (Luke 18:12). The imposition of set days of fasting is perhaps a mistake in this connection, since it leads to the formality which empties fasting of its true significance.”
R.D. Linder further advises, as seen in the Evangelical Dictionary of Theology,
“[T]here is psychological evidence that fasting lends itself to self-induced visions that sometimes prove harmful. On the other hand, there is biblical evidence that prayer and fasting together can be a useful part of individual and congregational life, though the practice should never be allowed to degenerate into an empty formal observance or a device for attempting to manipulate God.”
For much of the Messianic community, fasting may be limited to Yom Kippur and/or various other traditional Jewish fast days like the Ninth of Av. While these are useful times for corporate fasting, repentance, and reflection before the Lord—these need not only be the only times for Believers to fast. There are many times that we could fast from food and/or water, needing to focus our attention upon the Lord, completely independent of set times by either Scripture or tradition. And, there may be times in our lives when the Lord sets one of us on a forced-fast, as it were, when no matter hard we try we cannot eat, and He is trying to get our attention to press in to Him.
 Cf. David W. Bercot, ed., A Dictionary of Early Christian Beliefs (Peabody, MA: Hendrickson Publishers, 1998), pp 274-276 for a summary of positions in the Second-Fourth Century Christian Church on fasting.
 “Fasts,” in R.J. Zwi Werblowsky and Geoffrey Widoger, eds., The Oxford Dictionary of the Jewish Religion (New York and Oxford: Oxford University Press, 1997), 251.
 The significance of the Ninth of Av is probed in the article “Historic Anniversaries Contrasted” by Mark Huey, appearing in the July 2010 issue of OIM News.
 William Kelly, “Fast, Fasting,” in Everett F. Harrison, ed., Baker’s Dictionary of Theology (Grand Rapids: Baker Book House, 1960), 214.
 R.D. Linder, “Fast, Fasting,” in Evangelical Dictionary of Theology, pp 438-439.