Matt 6:16-18 (ESV)
And when you fast, do not look gloomy like the hypocrites, for they disfigure their faces that their fasting may be seen by others. Truly, I say to you, they have received their reward. But when you fast, anoint your head and wash your face, that your fasting may not be seen by others but by your Father who is in secret. And your Father who sees in secret will reward you.

A. Background

    Once a year the Jews have a compulsory fasting, which is on the Atonement Day (Lev 16:31). According to the Law, it is forbidden to eat, to drink, to bathe, to anoint, to wear soft shoes or to have sexual intercourse.

B. Reason and Significance

1. Mourning: Mourners are forbidden to eat meat or drink wine between death and burial.

2. Repentance:
    a. When Israel and Benjamin were having a civil war, the whole nation fasted. (Judge 20:26)
    b. Samuel proclaimed a general fasting when the people abandoned Yahweh to worship Baal. (1 Sam 7:6)
    c. Nehemiah proclaimed a general fasting for the confession of sin. (Neh 9:1)

3. Preparation for the receiving of revelations:
    a. Moses fasted for 40 days at Sinai. (Exo 24:18)
    b. Daniel fasted when waited for the words of God. (Dan 9:3)
    c. Jesus fasted when being tempted by Satan. (Matt 4:3)
    When the body is restrained, the function of the mind and spirit become most acute.

4. Pleading to God: When there is no rain in a prolonged drought and there may be no harvest, the whole nation would fast and plead to God for rain.

5. Entering into a fighting mode, seeking for alertness and power:
    i. Isa 58:6
    ii. Jesus fasted for 40 days to prepare for his ministry. (Matt 4:1-2)
    iii. Some kinds of demons and strongholds can only be cast out or destroyed with fasting. (Matt 17:21)

C. Types of Fasting

1. Strict Fasting
    Neither eating nor drinking for a short period of time. This is difficult, and may even be dangerous. We normally can restrain from eating for a certain period of time, but abstinence from water can only last for a few days. This type of fasting is practiced only in urgent occasions, and suggested to last for not more than three days.

2. Normal Fasting
    Abstinence from solid food for one to 40 days. Drinking of water or fluid is allowed. The body should be suitably adapted for a fasting for seven days or more, lest harm would be caused.

3. Partial Fasting
    Eating only at specific time of the day, and this type of fasting can be up to various length of time. Juices and unseasoned food are usually allowed, but meat or sugar is abstained.

D. Guide to Fasting

1. First of all, we should know that fasting is not harmful to a healthy person, but can be beneficial to the digestive system.

2. We would feel hungry when the meal time is passed, but this does not mean that we are in lack of nutrition. We have reserves of fat and starch in our body. Do not worry. The feel of hunger will fade gradually after about two hours.

3. If the hunger pang sustains, you may drink some water. Remember that we should take control of our own body, and not letting the body to control us. Be a master, and not a slave. When you endure, the hungry feeling would not bother you, and you mind would become more sober, because the blood would stay in the brain instead of in the intestine.

4. People with stomachache can drink a little bit of milk or dilute congee, but do not drink because of hunger. Drink water only if you do not have a stomach disease.

5. It is not advised to have heavy exercise during fasting. This would make you even hungrier, and sometime make you weak and lack of control. But normal activities should not be a problem.

6. You can work as normal. Keep a prayerful mind, and spare the meal times for prayers.

On Fasting