Fasting is a subject for which I have a lot of curiosity but little practice. It is the subject of an excellent and helpful little booklet by Daniel Hyde, part of the “Cultivating Biblical Godliness” series. He defines Christian fasting as “a religious abstaining from food or any other legitimate provision of God for a set period of time.” He addresses the practice of fasting with these 6 guidelines.
We fast freely. “Under the new covenant you are free to fast or not fast. There is no prescribed time of the year or week in which you must fast. There is no prescribed length of time for which you must fast. … There is no particular method required of you. In all of these you are free. … This point is so important to stress because if we began to regulate fasting beyond Scripture, then we would turn what should be done freely into an oppressive burden.”
We fast humbly. “We should look and act outwardly normal, while inwardly we must humble ourselves before God and seek His face in prayer. Your reward for this is that God sees, while your friends may not. Motivation does matter in fasting, then. The proper motivation behind our fasting is to have God as our reward rather than any human approval.”
We fast seriously. “Biblical fasting is not medical fasting or fasting to lose weight. This is serious business with God. … The seriousness of fasting implies some preparation, both bodily and spiritually. Again, we are free in fasting, but that does not mean that there are not some guidelines that are helpful to follow. Bodily speaking, prepare yourself for a fast the night before with enough rest, food, and water so that you will have strength to endure a fast. Spiritually speaking, set your mind upon the goal of your fast: seeking the Lord’s help for the matter for which you are fasting.”
We fast evangelically. It is important to qualify the above point about seriousness. Our fasting is serious, but we do not fast with all the outward rites and expressions of the old covenant. … Also, this means that we do not fast in a legal spirit, as if fasting somehow earned favor with God. … Since we are under the new covenant because of the work of Jesus Christ for us, we fast in a gospel-centered way. This means the believer’s fasting is an act of grateful response to Christ’s grace accomplished and applied to His church.”
We fast earnestly. In response to the gospel-centeredness of fasting, the temptation for us is to think the new covenant is a more ‘relaxed’ covenant. In contrast to this, it is because of what Jesus Christ has done that we must fast earnestly. In fact, we should fast with more eagerness and earnestness than those who fasted in the time of promise and shadow and not the time of fulfillment and substance.”
We fast prayerfully. “Fasting must be done prayerfully. … Fasting has an outward and an inward aspect. This is why our forefathers belabored the point that it is not fasting itself that brings us before the face of God, but the prayer that arises out of it. Fasting is an aid and help to prayer. Fasting, by itself, is not a good work; it is what we call an indifferent matter. Fasting is only a good work when it is linked to the purpose of prayer. This means that whether or not we fast, we can still pray. But if we don’t pray, fasting is futile.”