Note 1 at Mt. 4:2: Fasting is referred to 94 times in scripture. In the Old Testament, Isaiah 58:3-12 gives one of the clearest teachings on fasting. Jesus taught on fasting in Matthew 6:16-18. Most of the scriptures' teaching on fasting is by precept. There are at least 35 people in the Bible who fasted. Of these, three fasted forty days: Jesus (this verse), Elijah (1 Ki. 19:8), and apparently Joshua (Ex. 24:13-18). Moses fasted for forty days without food or water and then immediately (Dt. 9:9-25 with Ex. 32:30) repeated the fast, bringing his total abstinence to 80 days.

Fasting accomplishes many things. One of the greatest benefits of fasting is that through denying the lust of the flesh, the spirit man gains ascendancy. Fasting is a powerful weapon to be used in the battle described in Galatians 5:17. Fasting was always used as a means of seeking God to the exclusion of all else. Fasting does not cast out demons as Matthew 17:21 might suggest at first glance; but rather, it casts out unbelief because of the reasons mentioned above (see note 4 at Mt. 17:21, p. 213). Therefore, fasting is beneficial to every aspect of the Christian life--not only in the casting out of devils.

Without supernatural intervention, a person cannot fast without water for more than three days before he begins to die. The average person can only live seven days without water. However, a healthy person can fast from food for forty days before starvation begins to occur. Much of the "hunger pains" experienced at the beginning of a fast is just our appetite starving and will leave after a few days. When hunger returns at around forty days, starvation has begun and the fast should be broken unless it is a supernatural fast, as was the fast of Moses.

When ending a fast, one should use wisdom. Some people have died from eating "solid" food too soon. A general "rule of thumb" to be used for extended fasts (over 10 days) is to allow an equal number of days after the fast until you are back to eating normally.

The real virtue of a fast is in humbling ourselves through self denial (Ps. 35:13; 69:10), and that can be accomplished through ways other than total abstinence. Partial fasts can be beneficial, as well as fasts of our time or pleasures. However, because appetite for food is one of man's strongest drives, fasting from food seems to get the job done the quickest. Fasting should be a much more important part of our seeking God.