Fasting is the deliberate and prolonged abstinence from food and sometimes drink for a limited period of time. Its purpose, when rightly motivated, was to show godly sorrow and repentance for past sins (1 Sam.7:6; Joel 2:2-15; Jonah 3:5). Fasting was also enjoined in ancient Israel for mourning (2 Sam.1:12; 3:35 = 1 Chr.10:12; Judg.16:24), spiritual acts of piety (Lev.16), in the face of great danger when in sore need of divine guidance, while enduring tests and meeting temptations, or when studying, meditating or concentrating on Yahweh's purposes (2 Chr.20:3; Ezra 8:21; Esther 4:3,16; Mt.4:1-2). Fasting therefore lends an air of extra dedication to acts such as prayer and has the desirable affect of stilling the distractions of the fleshy nature, accentuating thereby sensitivity to the Ruach haQodesh (Holy Spirit) and therefore communiton with Yahweh (1 Ki.12:27-29; Jonah 3:5). Fasting is not (as in some traditions like Catholicism) a self-inflicted form of punishment but a humbling of the soul before El Elyon, the Most High.
Moses, Elijah and Yah'shua (Jesus) fasted for 40 days before the commencement of their ministries, with Moses and Elijah appearing with Yah'shua (Jesus) at His transfiguration (Mt.17:1-19; Ex.34:28; Dt.9:9; 1 Ki.19:7-8).
The Hebrew 'nh, usually translated 'afflict the soul', is often taken to include fasting (e.g. Lev.16:31, which elaborates the details of Yom haKippurim or the Day of Atonements) and thus an act of making teshuvah, i.e. repentance. We know that Paul, as a believer, fasted at Yom haKippurim (Ac.27:9) as required, and indeed kept the Torah right to the very end of his life) (Ac.13:9; 21:21; 22:3. Fasting annually for 24 hours at this sixth divine moed (appointment) is therefore required of all followers of Yah'shua the Messiah (Jesus Christ).
Isaiah 58 deals with a time when the sins of Judah were heavy but the people would not make teshuvah (repent), though they made a pretense of worshipping Yahweh, paying Him lip-service and performing religious devotions for show only. Fasting was one such devotion which they thought would give them divine notice and favour, yet they were bewildered when it seemed to have no effect on Heaven. Isaiah lists all the right and wrong reasons for fasting, making this an especially important source of instruction on the subject:
Even during the fast, while asking for Yahweh's righteous judgments and acting as if they carried on righteousness itself, they were yet pursuing their own pleasure and business, indulging in strife, oppression and violence. They showed none of the godly sorrow and teshuvah (repentance) associated with sincere, qadosh (holy, set-apart) fasts. Their fast was not such as to make their voice heard in Heaven though their showy wailings were noisy indeed. Accordingly, Yahweh denounced their hypocrisy in no uncertain terms.
"Cry aloud, spare not; lift up your voice like a trumpet; tell My people their transgression, and the house of Jacob their sins. Yet they seek Me daily, and delight to know My ways, as a nation that did righteousness, and did not forsake the ordinance of their Elohim (God). They ask of Me the ordinances of justice; tThey take delight in approaching Elohim (God). 'Why have we fasted,' they say, 'and You have not seen? Why have we afflicted our souls, and You take no notice?'
"In fact, in the day of your fast you find pleasure, and exploit all your labourers. Indeed you fast for strife and debate, and to strike with the fist of wickedness. You will not fast as you do this day, to make your voice heard on high. Is it a fast that I have chosen, a day for a man to afflict his soul?
Is it to bow down his head like a bulrush, and to spread out sackcloth and ashes? Would you call this a fast, and an acceptable day to Yahweh?
"Is this not the fast that I have chosen: To loose the bonds of wickedness, to undo the heavy burdens, to let the oppressed go free, and that you break every yoke? Is it not to share your bread with the hungry, and that you bring to your house the poor who are cast out; when you see the naked, that you cover him, and not hide yourself from your own flesh? Then your light shall break forth like the morning, your healing shall spring forth speedily, and your righteousness shall go before you; the glory of Yahweh shall be your rear guard. Then you shall call, and Yahweh will answer; You shall cry, and He will say, 'Here I am.'
"If you take away the yoke from your midst, the pointing of the finger, and speaking wickedness, if you extend your soul to the hungry and satisfy the afflicted soul, then your light shall dawn in the darkness, and your darkness shall be as the noonday. Yahweh will guide you continually, and satisfy your soul in drought, and strengthen your bones; you shall be like a watered garden, and like a spring of water, whose waters do not fail. Those from among you shall build the old waste places; you shall raise up the foundations of many generations; and you shall be called the Repairer of the Breach, the Restorer of Streets to Dwell In" (Isa.58:1-12, NKJV).
To be acceptable, fasting must be accompanied by reformation and restoration - a correction and putting right of past sins. Through His navi(prophet) Isaiah, Yahweh made known what He considered to be the results of a true fast - setting free the oppressed, feeding the hungry, clothing the naked and sheltering the homeless.
The Judeans established many fasts and at one time has four annual ones established outside of any Torah mandate. These were observed in much the same fashion as the ordained ones and Zechariah makes it clear that Yahweh did not have much regard for these at all (Zech.7:3-7; 8:16,19,23) - see Minor Judahite Fasts.
The claim is sometimes made that in Yah'shua's (Jesus') day the Pharisees as a group fasted twice a week, though there is no evidence for this and certainly none that any of the talmidim (dsiciples) of Yah'shua (Jesus) imitated them. We do know that the Pharisees ritually fasted "often" (Mt.9:14, NKJV), and not a few of these were hypocrites, one of whom indicated that he fasted twice-weekly and wore this as a badge of spiritual merit:
The Talmud speaks of one who "undertakes to fast every Monday and Thursday throughout the year" as not unusual but nevertheless not the norm (Ta'amit 12a). Some groups of Christians seem to imitate this practice, with at least one Anabaptist group fasting every other day.
"The Pharisee stood and prayed thus with himself, 'Elohim (God), I thank You that I am not like other men - extortioners, unjust, adulterers, or even as this tax collector. I fast twice a week; I give tithes of all that I possess'" (Luke 18:11-13, NKJV).
The Pharisees and some Anabaptists aside, fasting was, and is, a normal part of a believer's life.
Yah'shua (Jesus) taught specifically that fasting is not for display or for the approval of others, but between the individual and Yahweh:
Commenting on Matthew 6:16-18, Matthew Henry said:
"Moreover, when you fast, do not be like the hypocrites, with a sad countenance. For they disfigure their faces that they may appear to men to be fasting. Assuredly, I say to you, they have their reward. But you, when you fast, anoint your head and wash your face, so that you do not appear to men to be fasting, but to your Father who is in the secret place; and your Father who sees in secret will reward you openly" (Matt.6:16-18, NKJV).
Fasting is not for public display or approbation so that it may always be sincere.
"Religious fasting is a duty required of the disciples of Christ, but it is not so much a duty itself, as a means to dispose us for other duties. Fasting is the humbling of the soul, Psalm 35:13; that is the inside of the duty; let that, therefore, be thy principal care, and as to the outside of it, covent not to let it be seen. God sees in secret, and will reward openly" (Matthew Hebry's Concise Commentary on the Whole Bible, Thomas Nelson, Nashville, Tennessee: 1997, p.868).
The casting out of demons in deliverance ministry may on occasion require fasting:
"Then the talmidim (disciples) of John came to Him, saying, 'Why do we and the Pharisees fast often, but Your talmidim (disciples) do not fast?" And Yah'shua (Jesus) said to them, 'Can the friends of the bridegroom mourn as long as the bridegroom is with them? But the days will come when the bridegroom will be taken away from them, and then they will fast. No one puts a piece of unshrunk cloth on an old garment; for the patch pulls away from the garment, and the tear is made worse. Nor do they put new wine into old wineskins, or else the wineskins break, the wine is spilled, and the wineskins are ruined. But they put new wine into new wineskins, and both are preserved" (Matt.9:14-17, NKJV).
Because the words "and fasting" do not appear in some Greek MSS, there are those (like the Jehovah's Witnesses) who claim that fasting is not required of Christians. These words are, however, most definitely in the original Aramaic (e.g. AENT, HRV, Peshitta) so this claim is without any foundation. Their case is not helped by the fact that the first talmidim (disciples) most certainly did fast. When Barnabas and Paul were sent on a special mission to Asia Minor, there was fasting as well as praying. When elders were appointed in a new congregation, a very important task to ensure that Yahweh's will was followed, this was always done by the apostles:
"And when He came to the talmidim (disciples), He saw a great multitude around them, and Torah-teachers (scribes) disputing with them. Immediately, when they saw Him, all the people were greatly amazed, and running to Him, greeted Him. And He asked the Torah-teachers (scribes), 'What are you discussing with them?' Then one of the crowd answered and said, 'Teacher, I brought You my son, who has a mute spirit (demon). And wherever he seizes him, he throws him down; he foams at the mouth, gnashes his teeth, and becomes rigid. So I spoke to Your talmidim (disciples), that they should cast him out, but they could not.' He answered him and said, 'O faithless generation, how long shall I be with you? How long shall I bear with you? Bring him to Me.' Then they brought him to Him. And when he saw Him, immediately the spirit (demon) convulsed him, and he fell on the ground and wallowed, foaming at the mouth. So He asked his father, 'How long has this been happening to him?' And he said, 'From childhood. And often he has thrown him both into the fire and into the water to destroy him. But if You can do anything, have compassion on us and help us.' Yah'shua (Jesus) said to him, 'If you can believe, all things are possible to him who believes.' Immediately the father of the child cried out and said with tears, 'Master, I believe; help my unbelief!' When Yah'shua (Jesus) saw that the people came running together, He rebuked the unclean spirit, saying to it, 'Deaf and dumb spirit, I command you, come out of him and enter him no more!' Then the spirit cried out, convulsed him greatly, and came out of him. And he became as one dead, so that many said, 'He is dead.' 27 But Yah'shua (Jesus) took him by the hand and lifted him up, and he arose. And when He had come into the house, His talmidim (disciples) asked Him privately, 'Why could we not cast him out?' So He said to them, 'This kind can come out by nothing but prayer and fasting'" (Mark 9:14-29, NKJV).
All fasting, with the exception of the mandatory annual moed (appointment) of Yom haKippurim (Day of Atonements), is therefore strictly voluntary, but even the New Covenant Yom haKippurim fast, which is per force governed by grace, is not forced on nursing mothers, babes and very small children, or on those who may be physically weak or ill. There are therefore no other compulsory times of fasting and the addition of such (such as by the Catholic Church on Fridays during the 40 days of 'Lent' or on 'Ash Wednesday') are wholly without scriptural precedent or authority.
"While they were worshiping the Master and fasting, the Ruach haQodesh (Holy Spirit) said, 'Set apart for Me Barnabas and Saul for the work to which I have called them.' So after they had fasted and prayed, they placed their hands on them and sent them off" (Acts 13:2-3, NIV).
"Paul and Barnabas appointed elders for them in each assembly (church) and, with prayer and fasting, committed them to the Master, in whom they had put their trust" (Acts 14:23, NIV).
Fasting has been provided for us in mortality as an aid in the struggle between the spirit and the uncrucified fallen Adamic (carnal, fleshy) nature (Gal.2:20; 5:24). When we are not properly in Messiah by identification with His death and resurrection, that nature will come to the fore and incite us to rebel against Yahweh's Torah (Law) of mitzvot (commandments). Fasting may be used as a tool in Messiah's mitzvah (commandment) to the believer to put the flesh in its proper place in the grave.
Fasting, then, is one of the wings of prayer of the believer. (8 July 2017)
Though not mentioned in Scripture and beyond the scope of this sub-site, intermittent fasting (as opposed to dieting) as a pattern of eating (such as fasting for 16 hours and feasting within an 8 hour window) has been demonstrated to have medical benefits to the physical body by increasing life span, reducing the risk of diseases like cancer, reducing weight, overcoming gluttony and making the day simpler. There are different kinds of voluntary fasting (dry/'black' or wet) and for different durations (one or more days) which may be tailored to individual needs and dispositions.