Welcome to Ask the Church, our series where we seek to answer your questions about church worship, practice, or theology in under five minutes.
Today’s question is about fasting:
When do we do it? Why do we do it? How do we do it?
Fasting as Part of Christian Discipleship
I’m going to begin with the basic idea that fasting is sort of part and parcel with Christian discipleship. In the Sermon on the Mount, Jesus is giving instructions about tithing, prayer, and fasting. And He says, “When you fast.” He doesn’t say, “If you fast.” He just assumes that His followers will fast (Matthew 6:16).
There’s a moment in Mark 2:18–22 where the disciples of John the Baptist and the Pharisees are fasting, and Jesus’s disciples aren’t. People come up to Jesus saying, “Why don’t your disciples fast?” And in His response, what He says is that while the bridegroom—that’s Jesus Himself—is with them, fasting would be inappropriate.
The implication of that is that when the bridegroom is taken away, fasting is actually a normal practice (Mark 2:20). The other implication is that when we’re in heaven, face to face with the Lord, we will no longer fast. So here on earth, where we’re absent from the Lord in our body, fasting is a basic posture of discipleship (2 Corinthians 5:6–8).
The Church in Antioch
You see the Church living this out in Acts 13, in a description of the church in Antioch. At the beginning of the chapter, the leaders of the church are worshiping the Lord—and fasting (Acts 13:2). Fasting is presented as a basic part of Christian worship.
In the midst of that worship, the Holy Spirit arrives and tells them to set apart Saul (whom we know as Paul) and Barnabas for a new ministry. Their response to this commissioning is to fast and pray again before laying hands on them and sending them out (Acts 13:3).
In other words, fasting is just sort of woven through the fabric of the way that Christians worship and live together.
The Warnings: Matthew 6 and Isaiah 58
We need to listen to a warning before we plunge into the whys and the hows. And that’s the warning Jesus gives in Matthew 6. I want to add to it a warning that comes from Isaiah 58.
In Matthew 6:16–18, Jesus makes it very clear that fasting for the sake of self-promotion is completely in error. It’s wrong to fast for the sake of being seen as spiritual.
In Isaiah 58, we get the warning that if you fast while at the same time neglecting God’s commandments—in that chapter, the particular commandments in view are justice and mercy for those in need—then God won’t actually regard your fast (Isaiah 58:3–7).
What comes from both Isaiah 58 and Matthew 6 is this truth that I think is very helpful: fasting is done toward God. He is the primary audience. That’s why self-promotion in the midst of it—or rejecting His Word while doing it—is wrong.
Why Do We Fast?
If you were to summarize why we fast, there are two overarching reasons.
1. Penitence
This doesn’t mean that we earn forgiveness through fasting. It’s a way of responding to the gravity of our sin with sincerity—understanding how deep it is—but we’re not earning God’s forgiveness. We’re just being honest about how broken we are.
That’s the fasting you see on the Day of Atonement (Leviticus 16:29–31), or what the people of Nineveh are doing when Jonah preaches to them (Jonah 3:5).
2. Seeking God
The other reason why we fast is to seek the presence, or the will, or the guidance of God. That’s probably what’s going on in Acts 13, when the leaders of the church in Antioch are fasting—they’re waiting for God to show up.
It’s also what we see Moses doing at the top of Mount Sinai—fasting as he waits for God’s Word (Exodus 34:28).
In both of those instances—and many others—you get the sense that they’re foregoing food because they see that God’s presence and God’s Word are true life—true food (Deuteronomy 8:3; Matthew 4:4).
Fasting and Prayer Go Together
That actually helps us realize why fasting in the Scriptures is always joined to prayer. If fasting is about seeking the presence or the will of God… if fasting is penitence, when we acknowledge the gravity of our sin… then it makes sense that it would always be coupled with prayer.
In some sense, you could think of fasting as releasing our hold on ourselves—our strength, our life, our will—and prayer as grasping onto God’s will. It’s almost like fasting is a subcategory of prayer.
And that begins to explain why it would be so wrong to act in self-promotion while fasting, or to reject the commandment of God while fasting. Because if fasting is a part of the movement of prayer, then it’s actually something that’s incompatible with self-promotion or rejecting God’s will.
What’s clear is that fasting is something we do toward God as a part of our prayer life—not to earn His grace. In fact, we would say that fasting is a response to His grace, not a means of earning it.
How Do We Fast?
So then we jump into, very quickly: How do we fast?
The basic practice would be to forego a small meal and replace it with a time of prayer. That’s the sort of basic mode: to forego food, and then to actually replace it with prayer.
I would encourage you to start small. Don’t try to forego food for three days on your first go-round! Start with just lunch or just breakfast. Let your stamina build. Slowly grow in practice. Start with something sustainable.
What About Fasting from Things Besides Food?
I want to close with a question: what about fasting from non-foods like the Internet, or TV, or something like that? Or fasting partially from food—like from dessert or alcohol?
The thing I would say about those is that they’re very good practices. They reveal how much we depend on things that aren’t God. And they’re actually good ways of fasting—kind of like a subcategory of fasting itself.
But it’s important to note that fasting proper, in the Bible, always implies letting go of food. That reveals something important: food is integral to how God works with us. It’s the basic symbol of the fact that we’re in need. It reveals our vulnerability, our fragility.
And so we learn to let go of the very substance that we depend on for life itself—for this brief moment—to realize that our true life comes from God and His Word (Matthew 4:4).
I hope this answer helps! As always, if you have questions, send them to steven@incarnationrichmond.org.
And, as always, go in the grace of our Lord.