Why does fasting matter at all? Jesus assumes it. The disciples practiced it (Matthew 9:14). Jesus himself fasted forty days in the wilderness (Matthew 4:2). But most Christians today either have not fasted seriously or have no clear theology of why they would. The sermon offered a precise answer: we fast to nourish our hunger for God and to reduce our hunger for the world. That phrasing is worth holding carefully. Fasting is not primarily about abstinence. It is about appetite.
John Piper’s observation cuts deep here. The greatest enemy of hunger for God is not poison but apple pie. It is not obvious wickedness that dulls our appetite for the divine; it is the ordinary, comfortable pleasures of ordinary life. The food we love, the entertainment we have organized our weeks around, the ease and comfort we have mistaken for rest. None of these are sinful. That is precisely the problem. They are good gifts, given by a generous God, and they have the power to become so satisfying that there is no room left for hunger for the Giver. When the gift replaces the Giver, Piper writes, the idolatry is scarcely recognizable and almost incurable.
The medieval tradition described fasting as ‘a whole body listening,’ a way of recollecting who we are and who God is. When we voluntarily set aside a good gift, we are not engaging in self-hatred or ascetic punishment. We are making a declaration with our bodies: you are more than what you have given me. I am hungry for you, not just your gifts. The Father who sees this in secret, who watches the moment when a person chooses longing for him over the comfort of his gifts, is the Father who rewards. And the reward, again, is the relationship itself. The discipline opens the door; the Father is standing in it.