Fast - as per Webster's online 1913 dictionary - verb -
1. To abstain from food; to omit to take nourishment in whole or in part; to go hungry.
2. To practice abstinence as a religious exercise or duty; to abstain from food voluntarily for a time, for the mortification of the body or appetites, or as a token of grief, or humiliation and penitence.
I've been involved in a few discussions recently about fasting, so I'm trying to figure out what it means, and why you should or should not do it. So, I'm looking up fasting in the Bible. It seems like it was done mostly as an atonement for sins (1 Sam. 7:5-6), a cry for mercy, or a mourning, as when Saul died (2 Sam 1:12). People fasted in order to ask help from the LORD, as when Jehoshaphat proclaimed a fast for all of Judah because of the fear of their enemies (2 Chron. 20), or the fast of the Jews when Haman plotted to have them all killed (Esther 4).
Jesus also equated fasting with mourning, when he explained that his disciples had no cause to fast while he was still with them (Matt. 9:15). He also understood fasting as a way to greater faith in God, telling his disciples that they were unable to cast out a devil because their faith was small, and then saying in the next breath that it would only be cast out by prayer and fasting (Matt. 17:18-21).
The early church fasted when they needed to make decisions (Acts 13:1-3). Cornelius the centurion fasted and Peter was sent to him to bring him the gospel and baptize him (Acts 10).
I think the best passage about fasting is found in Isaiah 58:1-11 -
Cry aloud, spare not, lift up thy voice like a trumpet, and shew my people their transgression, and the house of Jacob their sins.
2 Yet they seek me daily, and delight to know my ways, as a nation that did righteousness, and forsook not the ordinance of their God: they ask of me the ordinances of justice; they take delight in approaching to God.
3 Wherefore have we fasted, say they, and thou seest not? wherefore have we afflicted our soul, and thou takest no knowledge? Behold, in the day of your fast ye find pleasure, and exact all your labours.
4 Behold, ye fast for strife and debate, and to smite with the fist of wickedness: ye shall not fast as ye do this day, to make your voice to be heard on high.
5 Is it such a fast that I have chosen? a day for a man to afflict his soul? is it to bow down his head as a bulrush, and to spread sackcloth and ashes under him? wilt thou call this a fast, and an acceptable day to the Lord?
6 Is not this the fast that I have chosen? to loose the bands of wickedness, to undo the heavy burdens, and to let the oppressed go free, and that ye break every yoke?
7 Is it not to deal thy bread to the hungry, and that thou bring the poor that are cast out to thy house? when thou seest the naked, that thou cover him; and that thou hide not thyself from thine own flesh?
8 Then shall thy light break forth as the morning, and thine health shall spring forth speedily: and thy righteousness shall go before thee; the glory of the Lord shall be thy reward.
9 Then shalt thou call, and the Lord shall answer; thou shalt cry, and he shall say, Here I am. If thou take away from the midst of thee the yoke, the putting forth of the finger, and speaking vanity;
10 And if thou draw out thy soul to the hungry, and satisfy the afflicted soul; then shall thy light rise in obscurity, and thy darkness be as the noon day:
11 And the Lord shall guide thee continually, and satisfy thy soul in drought, and make fat thy bones: and thou shalt be like a watered garden, and like a spring of water, whose waters fail not.
So God is not really impressed by our sacrifice. I guess that makes sense. He provided the ultimate sacrifice in the life of his own Son. Anything we could possibly do in our fleshly, selfish way can only pale in comparison. And simply going without food, entertainment, or comfort is not helpful to anyone. Our Christian walk is not really dependent on what we abstain from, as much as it is dependent on what we do with our resources. We could go without food and spend our food money on clothes. We could sacrifice our favorite TV program and spend the time reading a trashy novel instead. Whereas we may look like we're doing something for God, we're really just trying to look good without having to suffer.
God expects us to spend our lives for others, as he poured his out for us. Going without a meal may do nothing for us or for our relationship with God, but giving our meal to someone who is hungry will go a long way toward building His kingdom here on Earth. Skipping TV won't help us to hear God's voice if we replace it with anything other than God, but skipping TV to help someone who is sick or in trouble, or using that time to read the Bible and pray, can bring us closer to Him.
So...Should you fast or not? I think that depends. First, search your heart. Are you fasting to try to convince God to give you something you desire? Then it is probably not a good idea. Are you fasting to come closer to what God wants of you? Then it may be the right thing to do. I do not find anywhere that we are commanded to fast. What we are commanded to do is to love one another, and to take up our cross and follow Jesus. And since the cross is an instrument of death, we are to take seriously the admonition to die to self. Which means that our desires no longer matter, but only the desires that God has for us. And that, my friends, is a true fast.