A Firm Heart to Walk with God: 5 Reasons It Wavers

Introduction

On Friday, August 14, 2026, during the Teach & Pray at ICC TV Montreal, Pastor Joao Ahlin continued a series begun earlier in the year on discipleship and walking with God. That evening's theme carried a simple but demanding title: having a firm heart to walk with God. The question raised is not first about circumstances, but about inner disposition. Why does your heart waver at the very moment it should hold firm? Why does a good intention give way at the first resistance?

In this teaching, five reasons were brought to light. They are not theories. They describe what actually happens when a sincere child of God ends up stumbling right where they meant to stand firm. The message was built on powerful texts: the house on the rock, the call to Abraham to walk before God's face, the psalmist's cry, the promise of Isaiah. Through them, one conviction keeps coming back: everything begins with the heart. Here is an organized recap of this sermon, to help you meditate on it and pray it through for yourself.

Outline of the message

1. The battle of the heart: the house on the rock

The pastor opens the message with the parable in Matthew 7. Two men build. The rain falls, the floods come, the winds blow and beat against both houses. One stands, the other collapses. The difference is not in the storm, but in the foundation. The wise disciple built on the rock by putting Jesus' words into practice. The foolish one built on sand.

This image runs through the whole sermon. It reminds us that Christian stability does not come from quiet circumstances, but from a heart made firm in God. That is why the apostle Paul, in Ephesians 4:14, describes the purpose of the five ministries: that we may no longer be children, tossed back and forth, carried about by every wind of doctrine, by the cunning of men. And Proverbs 4:23 says it in one line: guard your heart above all else, for from it flow the springs of life. The heart is the site of the battle.

2. Joseph and Samson: two hearts, two outcomes

To show that the problem is never first the circumstance, Joao Ahlin sets two men side by side. Joseph, alone, exposed, with much to lose, refuses Potiphar's wife with these words: "How then could I do this great wickedness and sin against God?" His heart, before the scene ever played out, had already decided. There was no second option in him.

Samson, on the other hand, comes before Delilah with a heart already leaning. Seduction did not have to force a door open, it had been ajar for a long time. Samson let his heart love what it should not have loved, kept several options open, and his life was destroyed. The pastor returns to this point: the capacity to bear fruit, to be a disciple, to walk with God, is decided first in the heart. Before doubt, there is a heart that is out of alignment. Before the fall, there is an inner choice already made.

3. Five reasons why the heart wavers

The previous sermon had already dealt with the fear that pushes the heart to look for several options, using the image of Abraham who, at the first famine, leaves the promised land to go down to Egypt. God comes back for Abraham and reveals himself to him as El Shaddai, the all sufficient God (Genesis 17). He tells him: walk before my face and be blameless. In other words: stop looking for solutions outside of me, and your heart will find its firmness.

From there, the pastor lays out five further reasons why a heart, even a sincere one, can be found weak.

Reason 1: Fear and a divided heart

Fear is a subtle spirit. It does not attack head on, it slips into the heart the idea that you need a backup plan. It installs a divided heart, that way of loving God while still keeping a door open elsewhere. A double heart cannot display God in his fullness. It carries the vision up to the first obstacle, then sets it aside to look for a solution elsewhere. Abraham experienced this at the first famine, and David understood it in Psalm 51 when he pleads, "Create in me a clean heart and renew a right spirit within me."

Reason 2: Weakness and spiritual weariness

Proverbs 24:10 states it plainly: "If you faint in the day of adversity, your strength is small." The problem is not the temptation itself, it is that the inner person was not found strong enough to get through it. Many move forward with a drowsy spirit, rare prayer, a tired heart, and then wonder why they stumbled.

The good news is in Isaiah 40:29-31: God gives strength to the weary and increases the power of the weak. Those who wait on the Lord renew their strength, they mount up with wings like eagles, they run and are not weary, they walk and do not faint. Weariness is not the end. It is exactly the place where the Spirit comes to lift you up if you cry out to him.

Reason 3: Iniquity that is passed down

In Psalm 51, David acknowledges that he sinned with Bathsheba and had her husband killed, but he goes further: "I was brought forth in iniquity." The pastor explains the nuance: sin is an act, iniquity is a sin repeated so often that it ends up merging with the person and can be passed down to a generation through genes, through family environment, through blood.

This shows up in several ways. First, a habit repeated so often that the brain eventually records it as a norm, a second nature. Then, inherited dispositions: two children exposed to the same images do not react the same way, one becomes attached, the other does not, because something has already been sown. Finally, struggles that come back at the same crossroads: Isaac, in Genesis 26, is about to make the same mistake his father Abraham made during the famine. God appears to him and stops him: "Do not go down to Egypt, stay in the land that I will tell you." And he blesses him.

What God did for Isaac, he can do for you. Hebrews 4:12 reminds us that the word of God is a two edged sword, able to divide soul from spirit, able to cut through to the very thoughts of the heart. No habit, no inheritance, is too deeply rooted for his blood.

Reason 4: The enemy's flaming arrows

The psalmist speaks of arrows that fly by day. Sometimes they arrive through a dream that leaves a strange imprint, sometimes through an image seen in a movie, sometimes through a word received, sometimes through an exposure that seemed to carry no consequence. Their purpose is simple: to sting the soul, to revive an old inclination, to open a door that had been closed, to bring back a habit that had been set aside.

God's standard never changes: who shall ascend the hill of the Lord? The one who has clean hands and a pure heart. The arrows aim precisely to knock you off that standard. The answer is not guilt, but the blood of Jesus, applied in prayer, to pull out the arrow, erase the mark, and destroy the seed it wanted to leave behind.

Reason 5: Cages of the soul

Ezekiel 13:18-20 speaks of women who sew magic bands and make veils to hunt down souls. God is outraged and declares that he will tear off those bands and set free the souls caught like birds. The pastor applies this to spiritual prisons that seize the conscience. A person can be in the faith and yet have a captive conscience.

What are the signs? Moods that change with the seasons, emotional instability with no clear medical cause, what the ancients called lunatic behavior because it seemed to follow the phases of the moon. The world accepts it. In Christ, this is not normal. You can go through depression, but living with several personalities points to a spiritual reality that calls for deliverance. A heart whose conscience is captured cannot be firm with God. It fluctuates, contradicts itself, does not even understand its own reasoning. Here again, the blood of Jesus judges the cage and sets the soul free.

Key takeaways

• Christian stability does not come from calm circumstances, but from a heart founded on the rock of the word put into practice.
• Before the fall, there is always a heart that is out of alignment, keeping a second option, torn between God and something else.
• Spiritual weakness is not inevitable. God gives strength to the weary and renews the vigor of those who wait on him.
• Iniquity is a repeated sin that ends up being passed down. The blood of Jesus has the power to cut through what is rooted in habits, in blood, in the conscience.
• The enemy's arrows and the cages of the soul are concrete spiritual realities that prayer in the name of Jesus can break.

Personal application

Here are a few questions to help you take this message seriously, in your own walk.

Can you name, tonight, the backup option your heart is keeping "just in case" God does not answer? Where do you need to close a door?

When you look back at the last time you stumbled, was the real cause the circumstance, or a heart that was already tired and misaligned?

What repeated habit is becoming a second nature in you, to the point that you already find it normal? Who will you confess it to?

Is there, in your family history, a struggle that recurs from generation to generation, one you have never prayed against with authority?

What would it look like, very concretely, to spend a week "waiting on the Lord" as Isaiah 40 describes?

Verses cited

• Matthew 7:24-27 - the parable of the two houses, one on the rock, the other on the sand.
• Ephesians 4:14 - no longer being children, tossed about, carried about by every wind of doctrine.
• Proverbs 4:23 - guard your heart above all else.
• Genesis 17 - God reveals himself to Abraham as El Shaddai and tells him: walk before my face and be blameless.
• Ezekiel 2:1-2 - with the instruction comes the strength to obey: the Spirit entered me.
• Proverbs 24:10 - if you faint in the day of adversity, your strength is small.
• Isaiah 40:29-31 - those who wait on the Lord renew their strength.
• Psalm 51 - David confesses his sin and asks for a pure heart.
• 1 John 1:8-10 - if we confess our sins, he is faithful and just to forgive us.
• Hebrews 4:12 - the word of God divides soul from spirit and discerns the thoughts of the heart.
• Genesis 26:1-14 - Isaac, the famine, and God stopping him before he goes down to Egypt.
• Ezekiel 13:18-20 - God sets free the souls caught like birds.

FAQ

What is a firm heart, in the sense of this sermon?

It is a heart that keeps no backup option alongside God. A heart that, like the house on the rock, stands firm when the floods come, because it has put the word into practice and no longer looks for solutions outside of its Lord.

What is the difference between sin and iniquity?

Sin is an act of disobedience. Iniquity, according to the reading Joao Ahlin offers from Psalm 51, is a sin repeated so often that it ends up merging with the person, to the point of becoming embedded in habits, in the conscience, sometimes even in the family line. That is why it calls for a deeper prayer: to uproot, to separate, to erase through the blood of Jesus.

How do I pray concretely for a firm heart?

Pray from the texts in this message. Acknowledge before God the areas where your heart has been divided. Ask the Spirit of strength to come upon you, as in Ezekiel 2, where the Spirit enters to give the capacity to obey. Renounce tolerated habits, plead the blood of Jesus over what has been inherited, and make Psalm 51 your prayer: "Create in me a clean heart, O God, and renew a right spirit within me."