I think that many Christians have robbed themselves of one of the greatest tools in their spiritual lives: fasting. There is no one place that spells out how to fast! That is certainly one of the reasons we have been reluctant to teach on it. But, the Old Testament didn’t give much instruction on how to pray, just examples. People knew what the word meant. Jesus, in the New Testament, deepens the teaching on prayer but doesn’t change the essential definition of talking to God. In the New Testament, Jesus emphasizes the importance of not fasting like the hypocrites, but of fasting for God. But he still assumes people know the basic definition.
What is fasting?
The basic definition seems to be to not eat for a predetermined period of time. In 2 Samuel 12:16-7, David fasted and didn’t eat, but apparently still drank (water?). The Greek word for “fast” is actually “un-eating,” In Esther 4:16, drinking is also abstained from, but that seems to me to go beyond the strictest definition of fasting. That period of time should be set prayerfully sand carefully because it is better not to make a commitment at all than to break it (Ecclesiastes 5:4-5). People have fasted for many different lengths of time. Early Christians, following the Jewish custom, fasted two days a week. They chose Wednesdays and Fridays (commemorating the betrayal and crucifixion of Jesus). The Bible tells us of people fasting for a single day, three days, seven days and forty days (Moses, Elijah, and Jesus).
“The Fast” became a synonym for the Day of Atonement, the only fast prescribed in the law. In fact, it is not even explicitly called a fast in the Old Testament (but it is by Paul in Acts) – fasting is included in the broad “afflict your souls.” I think that makes it clear that fasting is a kind of mourning (Joel 2:14) of our separation from God, and was therefore not appropriate when Jesus was on earth (Matthew 9:15). It is a pretty natural connection from when we are grieving, we lose our appetite. Fasting is not always necessary but is a way of drawing ourselves closer to God. It is broad because it can represent repentance, a desire for revival or just seeking for God’s direction or action. But the idea of God’s distance is the same in all of them.
I think that Jesus’ quotation, when tempted of Satan, shows that fasting is voluntarily entering into the situation described in Deuteronomy 8:3. Being without food humbles us and teaches us to eat the hidden manna, the bread the disciples knew not of. That bread is the strength that comes from the Word of God (and especially the Incarnate Word). This is probably the passage I would use as my central text in a sermon on fasting, even though it doesn’t mention it specifically. God put the people in a forced fast, but I think the idea is clearly the same.
Jesus and the prophets condemned fasting with sin, or when fasting was just for show. I won’t detail those well known passages here, but our heart is key!
How do I start fasting?
Here is a sample prayer, demonstrating some elements of a fast.
“Lord, we come to you, humbly recognizing that we are not as close to you as we can be, and as we desire to be. We grow proud and self-sufficient in the illusion that we feed and clothe ourselves when we are as dependent on you for those things as the birds and the flowers are. We want to learn to be hungrier for you than we are for bread, which can only temporarily satisfy. We want to learn to draw our hunger from you, instead of from the dissolving world around us. We want to learn that we cannot live by bread alone, but must hang on your Word. So we commit to, with your help, abstain from all food and drink only water for three days.
During this time, every pang of hunger will not be an excuse to think of food, but a reminder to be hungry for you and to pray. As we recognize when eating is a habit, we will try to break the way we mindlessly structure our lives around it, and learn to make you the center instead. As we take the time we would have spent eating food feasting on your Word and praying, we are confident that you will draw us to yourself. Keep our eyes off the countdown to our next meal, and firmly on your face. We ask for freedom from hypocrisy and pretension, so those who see us will not see someone who is moody and hungry, but joyful and full of You.”
Obviously, when we are praying for specific guidance or intervention, we will tweak that some. But I think the basic idea is the same. People with medical conditions can “fast” with juice or whatever, as long as something is picked which does not undermine the entire point of mourning and self-denial. Fasting breaks the idolatry of the material world (or at least exposes it), practices self-denial in a culture which has never heard of it and is an unforgettable reminder of our real priorities.