The only thing most people know about fasting is that it can be a way to lose weight, but fasting is an important part of building a strong relationship with God. God desires and expects His followers to fast. When Jesus Christ was asked why His disciples did not fast, He replied with a short parable explaining it was because He was still present with them. He stated after He was no longer among them "then they will fast" (Matthew 9:14-15).

The Bible tells us Moses, David, Elijah, Ezra, Nehemiah, Esther, Daniel, Anna and Jesus Christ all fasted, and the Apostle Paul said he engaged "in fastings often" (2 Corinthians 11:27). Jesus did not instruct His disciples "if you fast" but "when you fast" (Matthew 6:17), emphasizing fasting as much as praying and doing good works

Fasting involves abstaining from food and drink while spending a lot of extra time in prayer, meditation and Bible study (Exodus 34:28; Ezra 10:6; Esther 4:16; Acts 9:9). It can be for a whole day, part of a day or more than a day. Ideally, we should spend most of the waking part of a fast period praying, studying and reflecting. If this is not possible, at the very least we can do that during the time we would be eating.

A healthy person can go without food and water for about three days before the body begins to be stressed. And a healthy person, who drinks water, can go without food for several days. Thus, the amazingly long 40-day fasts by Moses, Elijah and Jesus Christ (Deuteronomy 9:9; 1 Kings 19:8; Luke 4:2) were possible only by God's supernatural intervention.

How long we might safely fast depends on our individual health. Another option is a partial fast, such as that mentioned in Daniel 10:3. Here one takes in only as much food and/or water as necessary to be safe and spends extra time in prayer, Bible study and meditation. This, too, can be very profitable spiritually.

A major purpose of fasting is to learn humility—to better understand how great God is and how weak, sinful and needy we are. King David understood this when he wrote, "I humbled myself with fasting" (Psalms 35:13). In Matthew 5:3 Jesus said, "Blessed are the poor in spirit [humble and dependent], for theirs is the kingdom of heaven." Jesus made it clear if we fast to show off—to "appear to men to be fasting"—we are hypocrites and will have no reward from God (Matthew 6:16-18). Fasting with such a conceited attitude is worthless.

Godly fasting is poles apart from hunger strikes used to gain political power or draw attention to a personal cause. Fasting is an exercise in self-discipline over our fleshly cravings while keeping God first in our thoughts. It liberates us from slavery to our appetites while we focus on the true "Bread of Life," Jesus Christ (John 6:48-51).

There can be many reasons to fast, such as a personal problem, a difficult-to-overcome sin, facing a major decision, a Church crisis, a threat of danger, or expressing thanksgiving, among others. For an enlightening study, use a Bible concordance and look up all the passages that contain the words fast, fasted and fasting. Read why people fasted, what they were praying about and what God did as a result of the fast. Isaiah 58:1-12 is a profound passage that contrasts right and wrong attitudes in fasting. It clearly shows that fasting must not be a mere ritual.

The Bible has only one command regarding when to fast. God's people are commanded to fast on the Day of Atonement for 24 hours—from sundown to sundown (Leviticus 23:27-32). This fast day is listed among God's annual Holy Days. Besides the personal benefits of fasting, the Atonement fast has prophetic significance. To learn about the meaning of the Day of Atonement and its accompanying fast, read the free Bible study aid God's Holy Day Plan: The Promise of Hope for All Mankind.