If you have never fasted before, do not start off with a 40-day fast—unless you are very sure that God has called you to do this. The body grows accustomed to fasting by degrees, and God does not usually ask us to run before we have begun to walk. In fact, despite that fact that fasting is often depicted in Scripture as going without food, there are many other ways to fast. At its core, fasting is intended to take our eyes off of our physical needs/desires and subsequently fix our attention on God. Temporarily giving up other things that we often depend on (i.e. caffeine, television, etc.) can help us to refocus on our Creator and what He has for us.
During your fast, “Keep your servant also from willful sins” (Psalm 19:13, NIV) must be your constant prayer. Remember that asceticism may be as much “of the flesh” as overindulgence; the latter is a sin of the body, the former of the spirit. If the fast is to be for some days, there is a temptation as it approaches to overindulge. It is better to bend our wills in advance to the battle of self-discipline; it will ease the latter conflict. Finally, it is of supreme importance to approach this spiritual exercise as a fast of God’s choosing. It may help you to ask yourself the following questions:
1. Am I confident that this desire is God-given?
Would He have me undertake a normal or just a partial fast? “Jesus was led by the Spirit into the wilderness to be tempted by the devil” (Matthew 4:1, NIV).
2. Are my motives right?
Is there any hidden desire to impress others? “Your Father, who sees what is done in secret, will reward you” (Matthew 6:4, NIV).
3. What are my spiritual objectives in this fast?
Personal consecration? Intercession? Burdens? Revival? “I press on toward the goal” (Philippians 3:14, NIV).
4. Are my objectives self-centered?
Is my desire for personal blessing balanced by genuine concern for others? “In humility value others above yourselves, not looking to your own interests but each of you to the interests of the others” (Philippians 2:4, NIV).
5. Am I determined above all else to minister to the Lord in this fast?
“They were worshiping the Lord and fasting” (Acts 13:2, NIV). You should expect fasting to be, as it was for your Master, a time of conflict with the powers of darkness. Satan will often try to take advantage of your physical condition to launch an attack. Discouragement is one of his weapons. Guard against it by maintaining a spirit of praise.
Read through Ephesians 6 and equip the whole armor of God. Make use of the shield of faith to quench all of Satan’s flaming darts. In hand-to-hand encounters, use the sword of the Spirit, and tell Satan, “It is written…” Declare the victory of your great Captain over every principality and power.
Do not judge the efficacy of your intercessions by what you feel. Often in prayer and fasting you will find the going harder instead of easier. This is often when the most is happening this is wrestling. This is heavenly warfare. Your Captain did not promise a walk-over but a fight, and He gave you the weapons to win. Often you will not see the results until later, but the promise stands: “Your Father, who sees what is done in secret, will reward you” (Matthew 6:4, NIV).