One of the more misunderstood practices of godly people today is prayer and fasting. While fasting was required one day of the year (The Day of Atonement) in the Old Testament, there were many occasions where the people as a nation or as individuals fasted. These times of fasting were practiced in order to display a dependence on the Lord and to increase concentration on spiritual matters.
The New Testament scriptures do not command Christians to fast. At the same time, the bible presents fasting as something that is good, profitable, and beneficial. The Book of Acts presents Christians fasting before they made important decisions (Acts 13:2, 14:23). Fasting and prayer are often linked together (Luke 2:37, 5:33). Too often, the focus is on the lack of food. Instead, the purpose of fasting should be to remove our focus on the world in order to place it squarely on God. Fasting is a way to demonstrate to God, and to ourselves, that we are serious about our relationship with him. Fasting is designed to help us gain a new perspective and reliance on God.
Fasting does not always have to be about food. Anything given up temporarily in order to focus attention on prayer to God can be considered a fast, 1 Corinthians 7:1-5. Fasting should be set to a limited time, especially when fasting from food. Fasting is not intended to hurt the flesh or to lose weight, but to redirect attention towards God. Anyone can fast, but some may not be able to fast from food (diabetics, for example). Everyone can temporarily give up something in order to draw closer to God.
Fasting is not a way to get God to do what we want. Fasting is to change us, not God. Fasting is not a way to appear more spiritual than others. Fasting must be done in a spirit of humility and joyfulness, Matthew 6:16-18.