From the Old Self to the New Self


Date: August 17, 2025
Scripture: Colossians 3：8-10

Scripture Reading
Colossians 3:8–10 (ESV)
8 But now you must put them all away: anger, wrath, malice, slander, and obscene talk from your mouth.
9 Do not lie to one another, seeing that you have put off the old self with its practices
10 and have put on the new self, which is being renewed in knowledge after the image of its creator.

Introduction
In the past two weeks, I have spoken about brain chemistry and how circuits are formed by the over-secretion of dopamine. Especially last week, regarding immorality, passion, and greed, I explained how such circuits can be formed very quickly. Then, the brain begins to command behavior without passing through the prefrontal cortex — the “new brain” that is responsible for thinking and decision-making. This is the root of problems such as drugs, gambling, and addictions.
God created our brains in this way. Therefore, the prescription for this problem is to quit immediately — to cut it off. The Bible commands us to “put to death” such things. Thankfully, these neural circuits disappear when we stop using them. Even better, when we create new circuits and make them into habits, the brain will begin to use those circuits. That is what verse 1 means by “seek the things that are above” and “set your minds on things that are above.” This is the habit of spiritual living. When we continually seek the Word of God and the presence of the Holy Spirit, good circuits are formed. Praise, thanksgiving, and joy, when practiced habitually, form healthy circuits. Therefore, the biblical command to “rejoice always” is correct even from a neurological perspective.
Some might say, “Don’t bring brain science into a sermon; just speak spiritually.” But spirituality does not mean simply “pray more” or “attend more worship gatherings.” Those are important, but if we don’t know the method, we simply repeat the same failures. Using wise methods with the guidance and encouragement of the Holy Spirit is not wrong.

Today’s Focus: A New Command of Sanctification
Let us read verse 8 again:
“But now you must put them all away: anger, wrath, malice, slander, and obscene talk from your mouth.”
Last week’s sins — immorality, passion, and greed — were more personal in nature. Of course, immorality destroys families, and greed can ruin a family’s possessions, but ultimately the main victim is oneself. This week, however, Paul points to sins that harm others: sins that injure those around us.
“Soshiri” is not a familiar word in Japanese, but in English it is slander: it means words that harm others. People with sharp tongues must learn to speak graciously. Yet Paul’s teaching here goes deeper: it is about the evil thoughts that arise instantly in the heart and the malice that lingers until it turns into action.

Brain Function and Sinful Emotions
It is important to think here, too, about how the brain and brain chemistry work. Modern science may deny God, but it still identifies the problems quite well.
Last week, I spoke of dopamine. Normally, dopamine is meant to motivate us. But when it becomes excessive, it creates a powerful craving for “more.” This is why seeking pleasures beyond ordinary happiness becomes a problem.
In wealthy nations, people often have both money and leisure. The Bible teaches us to work six days and rest one day, but today people try to rest without working. This leads to seeking any kind of pleasure, including sexual pleasure, and the media promotes this as the path to greater happiness. Once such pleasure is experienced, normal happiness feels insufficient.
In poorer nations, people work hard during the day, and the joy of simply eating a meal after a long day’s work is profound. Hunger makes even ordinary food taste delicious. That is dopamine working as God designed.
Meanwhile, the wealthy avoid pain and suffering, but God has designed us so that enduring pain and hardship also releases dopamine. Dopamine is not just a “pleasure chemical.” It is a “reward prediction signal.” When we anticipate that “enduring this suffering will bring blessing,” dopamine is released.
So, when we think about heaven, glorification, and God’s promise to help us overcome trials, dopamine is released.

The Sad Side of Being Rich
I once thought happiness depended on whether you flew business class or economy. One time, due to an overbooking, I was upgraded to business class on a flight from San Francisco to Tokyo. The comfort, satisfaction, and sense of privilege were overwhelming. Yet, after 12 hours, I realized: business class was still not more comfortable than my own bed at home. It was more spacious than economy, but still confinement.
Meanwhile, I noticed a wealthy family in business class arguing angrily after the flight. I realized: those who endure economy class experience the relief and joy when they finally arrive — dopamine is released in their perseverance. Those who never endure, who lack hardship, do not experience this kind of joy.
Thus, we are deceived into thinking that a life without suffering or pain is true happiness. But neurologically and spiritually, it is the opposite: a life without trials lacks true joy. From a neurological perspective, a life without hardship or perseverance is a life without a true sense of accomplishment. As a result, the joy and fulfillment that come from dopamine remain shallow. This often leads people to seek false pleasures, such as gambling, drugs, or adultery, which ultimately bring unhappiness and downfall. Therefore, it is something to be thankful for when hardships and trials are given to us as needed.

Adrenaline
Now, let us consider adrenaline. Unlike dopamine, adrenaline is not a brain chemical but a hormone released from the adrenal glands, controlled by the “old brain.” Adrenaline switches the body into “emergency mode.” It gives us the power to fight or flee.
For example, when you encounter a bear in the forest, your brain predicts danger, and adrenaline floods your body, giving you extraordinary strength — the so-called “superhuman strength in emergencies.”
The problem today is that adrenaline, designed only for emergencies, is being secreted continually in modern life.

Anger and Adrenaline
When it comes to the issue of anger, the truth is that we often misunderstand it. First of all, anger itself is a natural and right response. We live in a culture where anger itself is considered bad. When someone gets angry, people say, “That person has a problem,” as if the anger itself were the problem. Or when a child gets angry, the parent simply scolds, saying, “Don’t be angry,” giving the impression that being angry is inherently wrong and that people who never get angry are good people. But in reality, the opposite can be true: a person who never gets angry, no matter what is done to them or how badly things go, may in fact have a deeper problem.
It is important to affirm anger as a natural response. What matters is teaching how to deal with anger in a healthy way. For example, if a child was promised a gift but didn’t receive it, it is natural for the child to feel angry. To simply say, “Well, it can’t be helped. Don’t be angry,” is the wrong approach. The right way is to acknowledge it: “Of course you’re angry—that makes sense.”
Paul says in Ephesians 4:26: “Be angry and do not sin; do not let the sun go down on your anger.”
Scientifically, adrenaline lasts only six seconds. Then, within the next 84 seconds, it dissipates. In total, anger physiologically lasts about 90 seconds. If we can wait out those first six seconds, the anger will fade.
But the Bible warns not about momentary anger, but about the anger that persists. Why? Because behind anger lies a deeper issue: malice (kakia in Greek), which corrupts character itself.

Secondary Anger
In fact, anger, wrath, and slander are often connected to what we might call “secondary anger.” Secondary anger is, in other words, the story we create in our own minds about the cause of our anger. During the 90 seconds that anger naturally lasts, we begin to interpret what happened—and in doing so, we create a story in which we keep assigning bad intentions to the other person.
For example, in response to a small, careless remark, we may form the story that “this person intentionally wanted to hurt me with an evil heart.” As a result, the feeling turns into malice within us. What may have begun as righteous anger gradually turns into a desire for revenge. At that point, the brain judges that there is an enemy and continues to release adrenaline. This cycle of 90 seconds is repeated again and again.
But adrenaline is designed to give us momentary strength in emergencies. When it is continually released, this powerful substance begins to damage our own bodies. That is why the Bible commands us not to hold on to anger.

Lying
Finally, Paul warns against lying: “Do not lie to one another.” This kind of lying is motivated by selfishness — to protect oneself, to seek gain, to look good, or to avoid responsibility. But lying destroys trust. And trust is the foundation of all relationships. When broken, friendships fade, reputation collapses, and isolation follows. Lies, when exposed, cause a person to lose trust. Someone who always lies is called “double-tongued.” Friends will begin to distance themselves, and that person’s reputation as a human being will decline. The foundation of human relationships is trust, and lying is a betrayal of that foundation. In the worst case, one loses social credibility and experiences what can be called a “social death.”
The Christian must avoid falsehood, even if honesty sometimes costs something.

Conclusion
The main theme today is verse 10: “Put on the new self, which is being renewed in knowledge after the image of its creator.”
Sin means “missing the mark” (Greek: hamartia, Hebrew: ḥaṭṭā’). It is walking the wrong path. Sanctification means turning from the wrong path to the right one.
We must ask: “Why should we do what is right?” Because doing what is right glorifies God and also leads to our true happiness.
In order to do this, we must throw away what is unnecessary in life.
Anger, rage, malice, slander, and lies—holding on to these things will never lead to true happiness. They must be discarded.
Some people buy new clothes, yet continue to keep the old ones. And sometimes, they still go out wearing those old clothes. They say, “Well, the new clothes don’t feel right, and I’m not used to them. The old clothes are comfortable because I’ve worn them for so long.” It is true—new clothes take time to get used to.
The same is true of the brain. Building new pathways is difficult. Living on a new foundation and with new values takes time to adjust to. But what is harmful must be thrown away.
To believe in the Lord Jesus means to become a new person.

Closing Prayer: 
Heavenly Father,
we thank You for teaching us today through Your Word to “put off the old self and put on the new self.”
So often we walk in anger and falsehood, yet You are renewing us in the likeness of Christ.
Help us to cast off evil and to put on the Lord Jesus, walking daily in His truth and holiness.
We pray this in the name of our Lord Jesus Christ. Amen.