I’ve never felt like I’ve understood fasting.

Of course, I’ve understood enough to know that fasting is an important part of the Christian life. Jesus explicitly stated, with reference to his disciples, “The days will come when the bridegroom is taken away from them, and then they will fast” (Matthew 9:15). Therefore, it’s clear that Jesus expects us to fast.

However, I’ve always wondered why. What’s the purpose of fasting? I certainly want to do it if I’m expected to do it, but I don’t want approach it the wrong way. If I’m going to put myself through such an uncomfortable ordeal, I definitely want to have a clear sense of purpose in doing so. I want to be absolutely confident that I’m not doing it all for nothing or, even worse, actually dishonoring God by engaging in a meaningless ritual.

Therefore, I picked up the best book I could find on the topic, A Hunger for God by John Piper. This book helped me see three significant purposes of fasting.

First, we fast in order to communicate to God how much we long for him. Fasting is saying, “God, I want you more than I want food.” As we fast with this mentality, we worship God by expressing the depth of our desire for him in a very visible way.

Second, we fast in order to practice preferring God to his gifts. So often, it’s not bad things that keep us from God but rather good things we enjoy too much. We enjoy God’s gifts so much that we forget about the One who gave us those gifts. But when we fast, we get much-needed practice preferring God above everything. As often as the thought of food enters our mind, we get to choose God all over again. Hopefully, the more practice we get, the more of a habit it will become.

Finally, we fast in order to confess our emptiness and need, expecting that God will put his glory on display by meeting that need. Just think: if there’s one thing God’s after, it’s his own glory. This is the purpose for which God created both the world (Romans 11:36) and specifically human beings (Isaiah 43:7). Therefore, when we humble ourselves before God by fasting while at the same time praying for specific needs, we give God occasion to demonstrate his glory by helping the helpless and meeting those needs. And when God sees such an occasion, he acts.