This is a re-post from something I wrote in 2008. As we pray and fast together, I thought it might be helpful for us to think about why we do something that can be very unpleasant.

Confession of a Pastor: I hate fasting.

That is true. At least, it used to be. It still is a little. But it’s changing in me mainly because I am just beginning to learn the reasons why the Bible tells us to fast.

Many Christians, in honest moments, agree with me. Fasting days put you in a bad mood. You rarely come out feeling more spiritual, you come out feeling like you could eat a raw goat.

The reason for that is that though many Christians know they ought to fast, but they don’t know why they fast. They know it is connected to prayer, but they don’t know what the connection is and, unfortunately, end up fasting in a way that is completely out of step with the Gospel.

Often, we fast because we assume that “punishing” ourselves somehow makes us and our prayers more acceptable to God. Fasting shows God how badly we want and deserve whatever we are asking for. God is moved, we believe, by our culinary flagellation and grudgingly grants us what we ask for, since we’ve suffered so much in our fast.

That, of course, is a not-even-very-well-veiled version of works-righteousness, and a flagrant denial of what the Gospel teaches us about God. Rather than making God more willing to answer our prayers, it offends God by trampling on the cross of Christ—and I don’t see how ticking God off is any help to our prayer lives!

So then, why do you fast, and how do you do it in a way pleasing to God? I’ll give you two reasons.

To give God a chance to purify our hearts from idols:

Scripture says that when our prayers aren’t answered, it’s not because of unwillingness on God’s part. It’s usually that our motives aren’t pure (James 4:1-6). James says we pray like adulterers and idolaters, who feel like we need the anwswer to our prayer in order to be happy, rather than being fully happy in Christ. Fasting helps us focus our motives—reminding us that all we need is Christ, and nothing else.

I have found that I quickly turn every good thing on earth into an idol. I feel like I need that THING to be happy: money, health, the approval of others, etc. I have found that even ministry success can become something I feel like I need to feel like I am ‘worth’ something. Thus,  when I am praying for one of these things, often I am asking God to give me something so I can find in that thing what I should be finding in Him. I’m praying like an idolater.

So, quite often God takes away blessings from our lives to remind us that we can be satisfied in our relationship to Him even if we have nothing else. This “suffering” He inflicts is not punishment but training in obedience to the first commandment to have no other gods but Him.

Fasting is a way of suffering “voluntarily,” to train yourself to not become so addicted to the gifts of God in your life that you turn them into idols.

This is what Jesus was doing in the when he fasted for 40 days in the wilderness. He told his body, “I don’t live by bread alone. My real “food” is feasting on the presence and glory of God. As John Piper says, seeing the glory of God is to be the all satisfying treasure of our faith.

When our motives are purified, then, as James says, our prayers become much more powerful. When you don’t need the answer to your prayer to be happy or fulfilled because you are satisfied in the knowledge of God, then your chief motive in prayer can be the glorification of God. And when the glory of God, and not the acquisition of idols, is your motive, then God loves to pour out His gifts. He’s a Father, after all, and one who loves to give.

So, fast to purify your motives. As the old Puritans used to say, “One pure motive in prayer is worth more than many words.”

When I fast, I often think about how much I desire ministry success as a means for the promotion of my own reputation or because it will lead to greater earthly rewards. (That’s why I get worried when I think something in ministry might fail, or jealous when I see another really effective pastor.) But when I fast, I focus on the fact that I need neither earthly acclaim nor physical wealth to be fulfilled. I have God as a Father, and my motive is His glory on earth and the salvation of people whether or not it is advantageous for me. Fasting teaches me to ask not so “my kingdom might come” but so “thy kingdom might come.”

To give us a greater sensitivity to the “voice” of the Spirit:

The appetites of our body often clamor so loudly in our souls that we are not able to hear the “still small voice” of spiritual passion. I hesitate to use the word “voice” as if to imply I’m talking about an inaudible whisper where God tells you some specific plan he wants you to follow. God may do that sometimes, but that is not what I am here referring to. Rather, it is the voice of spiritual passion: a desire to see God glorified; a desire for people come to Christ; and love of spiritual things. Fasting helps silence the voice of our body so that we can more greatly hear the voice of the Spirit.

Now, I know what you might say: “Wait! This works completely backwards for me. When I fast, all I can hear is my body screaming about how hungry I am!” Ha. Me too. But fasting is more training to hear the voice of God, to break the power of your body over you. When you are not satisfying your body’s desire for food, you are saying, “Listen! You are not in charge! The Spirit is in charge of me.” This is what Jesus was training himself to do when He fasted for 40 days in the wilderness. He developed sensitivity to the Spirit by desensitizing himself to his body.

When sinful motivations dominate our hearts, God’s power in and through us is quenched.  Fasting helps break the power of those motivations over us.

This is not the whole picture of why we fast, but it should get you started. The most important thing to remember is that fasting NEVER earns the favor of God or increases God’s willingness to answer our prayers. The Gospel is that God could not feel more favorably about you than does in Christ. Fasting doesn’t change God; fasting changes us.

Fasting is a spiritual discipline that trains your heart to love God and His glory more. Spiritual disciplines are not meritorious or power-generating in themselves, they help connect us to power. As Puritan John Owen says, “Fasting, memorization, meditation and Bible reading have their place in order… but they are to be looked on as the streams, whereas we often (mistakenly) look on them as the fountain.” When we love God with a pure heart, God can pour out His blessings in an unfettered way on us. (James 4:1–2; 5:16; Isaiah 59:1–2.)

So, church, use fasting to search your heart and train it to love the glory of God supremely, and then ask for a ridiculous amount of God’s glory to be poured out through us!

We aren’t asking for God’s blessings for our benefit—i.e. we don’t need that success in order to validate us before God, or prove that we’re right or have it together—because we have that in Christ. We are only asking for the sake of God’s name in this area. Isa 26:8.

If you’d like to delve more deeply into this, check out John Piper’s A Hunger for God. It’s a great devotional read.