Fasting can feel strange to modern Christians.
Some assume it’s outdated. Others assume it’s extreme. Still others treat it as a spiritual power move — something that pressures God into action.
But what if fasting isn’t about manipulating God at all?
What if it’s about God reshaping us?
In Isaiah 58 and in the teachings of Jesus, fasting is not presented as religious performance. It is presented as spiritual formation — a practice that moves us from religious acting to religion in action.
What Is Fasting, Really?
Biblically, fasting is a temporary, voluntary refraining from food (and sometimes drink) for a spiritual purpose.
It is:
- Chosen
- Temporary
- God-directed
- Rooted in trust and submission
It is not a spell.
It is not leverage.
It is not a way to force heaven’s hand.
Fasting is an embodied way of saying:
“God, I need You more than I need this.”
Fasting Gone Wrong (Isaiah 58)
Isaiah 58 gives us a startling example of fasting that God rejects.
The people are fasting. They are seeking God. They are humbling themselves.
But God says:
You fast and exploit your workers.
You fast and quarrel.
You fast and strike with wicked fists.
You fast and point fingers.
Their fasting is religious — but not spiritually authentic.
It is religious acting, not religion in action.
They bow their heads like reeds. They wear sackcloth. They look the part.
But their lives contradict their ritual.
And God says plainly:
“Is this the kind of fast I have chosen?”
The Fast God Chooses
Then Isaiah pivots.
True fasting, God says, looks like this:
- Loosing the chains of injustice
- Breaking every yoke
- Feeding the hungry
- Clothing the naked
- Sheltering the poor
- Refusing to turn away from your own flesh and blood
Does this sound familiar?
It should.
It sounds like Jesus.
In Matthew 25, Jesus identifies His true followers by six acts of mercy:
- Feeding the hungry
- Giving drink to the thirsty
- Clothing the naked
- Welcoming the stranger
- Visiting the sick
- Visiting the imprisoned
Isaiah. James. Jesus. All agree:
Authentic religion acts.
Fasting that doesn’t move us toward mercy has missed its purpose.
Fasting Changes Us First
Notice something critical in Isaiah 58:
Fasting is not about changing “them.”
It is about changing me.
The people in Isaiah were fasting while hoping God would fix the nation.
But God tells them the fast He chooses reforms the heart first — and then flows outward in justice and compassion.
Fasting is useful because it softens us.
It disrupts our patterns.
It exposes our cravings.
It humbles our pride.
It aligns our hunger with God’s hunger.
Fasting and Spiritual Formation
The New Testament deepens this.
Paul writes that we are being conformed to the image of the Son (Romans 8:29).
Luke records Jesus saying:
“Everyone who is fully trained will be like his teacher.”
You are becoming someone.
The question is: who?
Spiritual formation means your soul is being shaped — either toward Christlikeness or away from it.
Fasting plays a role in that shaping..
Jesus and the Question of Fasting
When people questioned Jesus about why His disciples didn’t fast like the Pharisees or John’s followers, He responded with imagery.
He said you don’t fast at a wedding feast while the bridegroom is present.
But then He said something often overlooked:
When the bridegroom is taken away, they will fast.
Jesus did not abolish fasting.
He reframed it.
Then He used two metaphors:
- You don’t patch old garments with unshrunk cloth.
- You don’t put new wine into old wineskins.
What does that mean?
The old way of fasting — done for visibility, prestige, or religious clout — cannot contain the new life Jesus brings.
Fasting must match the new heart.
Disfigured Faces and Distorted Souls
In the Sermon on the Mount, Jesus teaches directly on fasting.
“When you fast, do not look gloomy like the hypocrites… they disfigure their faces to be seen by others.”
Here’s the danger:
When fasting becomes performance, the face is distorted — and so is the soul.
Outward distortion reveals inward deformation.
But Jesus offers the opposite:
- Wash your face.
- Anoint your head.
- Keep it secret.
Not because appearances matter most — but because formation does.
True fasting beautifies the soul.
It makes you radiant, not resentful.
Gentle, not superior.
Joyful, not self-righteous.
The Hidden Place
Jesus says your Father sees in secret — and rewards in secret.
Fasting creates a hidden meeting place with God.
This does not mean suppressing grief or pretending everything is fine.
It means there is a sacred interior space where:
- You lament.
- You repent.
- You consecrate.
- You discern.
- You commune.
Fasting is relational.
It is not public spectacle.
It is private surrender.
What About Rewards?
For many Protestants, the word “reward” can feel uncomfortable.
Isn’t salvation by grace alone?
Yes.
But Scripture repeatedly affirms that God rewards His children.
It is not sinful to desire the rewards of God.
It is sinful to desire the rewards of the world more.
When Jesus says the Father will reward you, He means something deeply relational.
The reward is:
- Deeper communion.
- Greater clarity.
- Increased joy.
- Stronger formation.
- Undescribed and perhaps indescribable grace.
What Fasting Actually Costs
Biblical fasting is from food.
Abstaining from social media, alcohol, or chocolate can be beneficial — but that is abstinence, not fasting.
Food is necessary
Fasting means temporarily giving up what you need for what you need more.
Jesus fasted forty days before launching His ministry.
The point wasn’t extremity.
It was dependence.
What Do You Need More Than Your Next Meal?
This sermon ends with piercing questions:
- Is there nothing left you need at a deeper level?
- Is your hunger being numbed by constant consumption?
- When you feel restless, do you fill the emptiness?
- What do you need more than your next meal?
And perhaps the most powerful question:
What might God rebuild through us if we were willing to be hungry for what He hungers for?
Isaiah promises:
- Light will break forth like the dawn.
- Healing will appear.
- Ancient ruins will be rebuilt.
- You will be called repairer of broken walls.
Fasting moves us from self-preoccupation to kingdom participation.
Final Invitation
Fasting is not:
- Pretension
- Obligation
- Religious theater
It is:
- Formation
- Dependence
- Hidden communion
- Preparation for mercy
When we fast to be formed by Jesus, someone else gets fed.
When we hunger for God, someone else finds justice.
When we surrender our appetites, our hearts soften.
And perhaps — just perhaps — we become the kind of people who repair what is broken.
