Fasting in the Old Testament was combined with wailing in sackcloth and ash to demonstrate true repentance for sin and to avoid God’s wrath. However since God isn’t in the punishing business anymore (1 John 4:18) and all the sins of a believer are forgiven when they become born again (Col 2:13), fasting for this purpose is senseless and rejects what Jesus accomplished at the cross.
Some people interpret Isaiah 58 as the type of fast that would please God under the New Covenant, however the context of this chapter is clear from the first verse:
The LORD says, “Shout as loud as you can! Tell my people Israel about their sins! (Isa 58:1 GNB)
If we read the entire chapter it’s clear that this was addressed to Israel under the Old Covenant. Even though some of the principles may seem good and righteous (i.e. to remove the chains of oppression, share their food with the hungry, do not refuse help to their relatives, etc. in verses 6-7), it is still clear God’s blessings in this chapter were dependent on Israel’s ability to perform these deeds. It actually becomes blatantly clear in the last two verses:
The LORD says, “If you treat the Sabbath as sacred and do not pursue your own interests on that day; if you value my holy day and honor it by not traveling, working, or talking idly on that day, then you will find the joy that comes from serving me. I will make you honored all over the world, and you will enjoy the land I gave to your ancestor, Jacob. I, the LORD, have spoken.” (Isa 58:13-14 GNB)
Under the New Covenant, God’s blessings do not depend on our proficiency in executing the 10 Commandments – Jesus Christ accomplished it all! Now we are blessed simply because we have faith in Jesus:
This means that everyone who has faith will share in the blessings that were given to Abraham because of his faith. (Gal 3:9 CEV)
Fasting to Drive Out Demons
When Jesus’ disciples could not evict the demon from the young boy and afterwards questioned why, Jesus answered them:
19 Then the disciples came to Jesus apart, and said, Why could we not cast him out? 20 And Jesus said to them, Because of your unbelief. For truly I say to you, If you have faith like a grain of mustard seed, you shall say to this mountain, Move from here to there. And it shall move. And nothing shall be impossible to you. 21 However, this kind does not go out except by prayer and fasting. (Matt 17:19-21 MKJV)
Jesus’ answer in verse 21 did not refer to the demon – He was referring to their unbelief. He was saying “this kind (of unbelief) only goes out by prayer and fasting.” Jesus was simply expounding on His answer in verse 20 by telling them the secret of how to get rid of their unbelief.
So a fast is sometimes good for us, to rid us of our unbelief and to discipline our flesh. But it’s not to be used when asking God for something. What do we try to accomplish by accompanying a prayer request with fasting? Are we trying to prove to God that we are really serious? Do we need to beg and plead with our earthly fathers and throw in a fast for good measure when we ask them for something? Of course not!
We need not act as if we have to change God’s mind all the time, as though He doesn’t really want to bless us. His love for us is infinitely deeper than that of our earthly dads; God doesn’t need to be convinced of our intentions – He is on our side!
The Purpose of Fasting
The following are extracts from a great article written by author Ralph Harris from Life Course Ministries, entitled “A Needle to My Heart” (http://lifecourseministries.blogspot.com/2011/05/needle-to-my-heart.html):
I’ve been fasting this week. It’s not because God likes it when I fast, it’s because I do. Yeah, you read that right. For me, fasting is choosing a weakness through which I will know and savor God more. It’s all about satisfaction – mine.
In this case, I’m fasting from food, but in the past I’ve fasted from television, music (rather than listen to the stereo in my car on morning drives to work, I preferred thinking and listening for Him in quiet), news media, alcohol (I like an ale or a glass of wine now and then), and more.
It’s amazing how much I get used to turning to the things of this world for satisfaction, rather than to God, who satisfies me most and best. Like many, I suppose, seeking God or reading the Bible or praying can become all about obedience and willpower (“I’ve got to do it!”) when I’m getting more satisfaction and better pleasure elsewhere. Does that make sense?
I start to approach God and the things He likes as important things to do, rather than ways to know Him and like Him. And what about letting Him show me why He likes me? Reading the Bible and praying becomes a daily duration of time when I get my study and devotional time card punched. Thunk-thunk! Going to church becomes all about following through on commitment. Giving money is about the pledge I made. Yuck. Round about then a college football game is much more exciting, or a bowl of ice cream, a shopping spree, a good movie, or a new electronic gadget. What delight, right?
God no longer brings about the wedding of desire and satisfaction—fulfillment—because it has been joined together elsewhere. What does God get? Commitment and Study and Pledges of Obedience—and my frustration. A lot of frustration.
But because He has crucified me to this world and this world to me (we’re incompatible), I can tolerate this hostage situation for only so long (Gal. 6:14). A break-out is drawing near.
That’s where a fast comes in. Through it I am needling myself, my true self, and saying, “Alert! Wake up and be satisfied! I can no longer stand surface satisfaction when I’ve been made for far deeper.” To be sure, I still have strong longings for satisfaction—in fact they get stronger—but the Spirit brings out desires now natural for me. I actually want God. I truly want Father.
To be clear, no one has to fast to earn anything. It’s a way of enjoying what you already have. Any kind of fasting is toward satisfaction. It’s a way of acknowledging, “Jesus, you have given me absolutely everything already for entirely nothing. Hooray! I’m full already. So I want to hunger as a way of finding fullness.”