Feed Your Soul, Starve Your Idols
In this week’s sermon, we talked about self-control and the reality that we don’t outgrow the marshmallow test. We just trade marshmallows for other things. Every day we face moments where we’re tempted to grab what feels good now instead of waiting for something better. Proverbs tells us that wise persons live self-controlled lives. But how do we actually grow in self-control?
If self-control isn’t just about willpower how do we train our hearts to love the greater reward? One of the most practical and often neglected answers is fasting.
Fasting Trains the Heart
Proverbs 18:10 says, “The name of the Lord is a strong tower; the righteous man runs into it and is safe.”
In the sermon, we said that most self-control problems aren’t addiction problems, they’re refuge problems. When stress hits, we run somewhere. When loneliness hits, we run somewhere. When insecurity hits, we run somewhere. Fasting is a way of retraining where we run.
To paraphrase Donald Whitney in his great work Spiritual Disciplines for the Christian Life: Fasting is a temporary physical demonstration that we believe the truth declared by the gospel, namely that, ‘Man shall not live by bread alone, but by every word that comes from the mouth of God.’ When we fast, we are saying with our bodies what we claim with our mouths: God is our true sustenance.
John Calvin identified three purposes of fasting:
To weaken and subdue the flesh.
To prepare us for prayer and meditation.
As a testimony of humility before God.
In other words, fasting exposes what controls us and helps loosen its grip.
Starving the Substitute
Self-control isn’t about loving sin less; it’s about loving Christ more. Whatever you love most will control you. John Piper writes in A Hunger for God, “The birthplace of Christian fasting is homesickness for God.” Fasting isn’t about proving our devotion. It’s about intensifying our desire. It’s about saying, “God, I want You more than I want this.”
When we skip a meal, we feel hunger. That hunger becomes a signal. Instead of immediately satisfying it, we redirect it into prayer. We let the physical ache remind us of a deeper spiritual need. Piper goes on to say, “Fasting is a way of saying with our stomach and our whole body how much we need and want and trust Jesus.” Every rumble becomes a reminder: there is a greater reward.
And here’s why that matters for self-control.
If you can learn to say “no” to a legitimate desire (food), you are training yourself to say “no” to illegitimate ones (sin). One of my favorite pastors, Alistair Begg, once described fasting as a practical expression of self-control not to punish the body, but to train it. You are teaching your heart that it doesn’t have to obey every craving.
Running to the Strong Tower
In Matthew 6:16, Jesus didn’t say “if you fast.” He said, “when you fast.” Fasting is meant to be normal for the Christian life. But it must always be connected to prayer. Fasting without prayer is dieting. Fasting with prayer is worship. When you feel hunger and turn to Scripture instead of the fridge, you are running to your strong tower.
When you feel the urge to scroll and instead pray, you are running to your strong tower.
When you feel the impulse to numb out and instead sit quietly before God, you are running to your strong tower. Fasting is not about earning favor with God. It’s about training your affections. It’s about feeding your soul and starving your idols.
A Practical Guide
If you’ve never fasted before, start small:
Skip one meal (lunch is often easiest).
Use that time for prayer, Scripture, or worship.
Let your hunger prompt you to pray.
Then allow yourself to grow from there:
Fast from sunup to sundown.
Fast from something specific like social media, entertainment, or unnecessary spending but always connect it to prayer.
Remember, the goal isn’t suffering. The goal is dependence.
A Challenge for This Week
This week, I want to invite you into something specific. Fast for 24 hours. From dinner one evening to dinner the next. When hunger hits, pray. When weakness comes, open your Bible. When you feel the pull toward distraction, run to the strong tower. Let your body teach your soul.
Because wise persons live self-controlled lives and self-control grows when our love for Christ becomes stronger than our appetite for substitutes. There is a greater reward.
Feed your soul.
Starve your idols.
— Pastor Jeremy
1 Institutes of the Christian Religion, Book IV, Chapter 12.
