Pastor John, what is the purpose behind fasting? Richard Foster wrote a book on spiritual disciplines, and in it he says that probably the most important text in all the Bible for establishing the importance of Christian fasting--Christian fasting--that we should do it today is Matthew 9, 14 and following. Let me read just a couple of verses of that and show you the sentence that I think he's right about.

The disciples of John, John the Baptist, came to Jesus and said, "Why do the Pharisees fast, but your disciples do not fast?" So he's not fasting. And Jesus said to them, "Can the wedding guests mourn as long as the bridegroom is with them? The days will come when the bridegroom is taken away, and then they will fast." Now that's the sentence that Foster says, and I think he's right, shows that in Jesus' mind, when he is taken away--that is, when he dies and ascends to the Father--there will be fasting.

And therefore the context of fasting in Jesus' mind is longing for the "not yet" of the kingdom. So he's come, and while he was here, they didn't fast because the bridegroom was present. But when the bridegroom is taken away to come a second time, there's this "ache" in the heart of God's people.

And I think that's the general statement about the meaning of fasting. Fasting is a physical exclamation point at the end of the sentence, "I need you. I want you. I long for you. You are my treasure. I want more of you, and oh for the day when you would return.

Maranatha! Come, Lord Jesus!" And fasting is an exclamation point at the end of all those sentences. So the heart of it is longing, and a putting of our stomach where our heart is, in order to give added intensity and expressiveness to our ache for Jesus, and our longing or our ache for all the implications of Jesus' power in the present moment that isn't completely realized.

We want to see people healed, we want to see people saved, we want to see marriages redeemed, and we ache and long for this to happen, and therefore we ask Jesus to come by putting this exclamation point of longing at the end of our our desires. Here's one more thing, and I say this largely from experience, and people can test whether they think it's got biblical root or not, I think it does.

I think fasting is not only a positive statement of "this much I want you, you're more important to me than food," but it's also a negative way of exposing latent idolatries. When I'm not being medicated by food, what comes out of my heart? Anger? Lust? The need for television and more and more of it, or something like that?

People need to know what's at the bottom. I think Job was a good man, basically, but at the bottom of Job's life was some latent sin, and when God took away from him health, took away from him children, in other words, this was a horrible enforced fast from children and from health, Job got bent out of shape and said some things for which he had to later repent.

And I find, Tony, that if I go without, say, 24 hours of food from from supper to supper or breakfast to breakfast or something like that, my, oh my, what is exposed of my heart towards my wife and my daughter? So it is a very good discipline, not only as a positive expression of longing in prayer, but also a negative exposure of my heart so that I can deal with these things as they come up.

Thank you, Pastor John, and for more on fasting, see John Piper's book "A Hunger for God," which you can download for free online at DesiringGod.org. I'm your host, Tony Reinke, thanks for listening.