Dr. Caroline Leaf is an incredible Christian neuroscientist that is spreading the truth about the incredible power of our minds over our body and life.

I love to take the books I read and pull out 5-7 of my favorite key ideas/insights and actions steps that I personally have taken and applied to better my life and the lives of those around me.

Switch on Your Brain by Dr. Caroline Leaf

1. The Science of Thought

We have two minds: Conscious & Subconscious


  • Only consists of the thoughts you are intentionally choosing to think.
  • Only contributes to 5% of our daily behaviors.


  • “As a man thinks in his heart, so is he” – Prov 23:7 – your true heart and identity is your subconscious.
  • Controls how we perceive life, how we react to situations, what we think about ourselves, and what we can accomplish.
  • It is programmed based on each thought, action, emotion, and experience we have ever had in life.
  • Your subconscious is what is running you 95% of the time.
  • When you are not conscientiously thinking (when your mind wanders, when you react to situations without thinking, and when you are driving and you realize you have zoned out) your subconscious is what is operating and driving you on autopilot.

Your Reality

  • Perception is reality. We are all perceiving this life completely differently right now based on the filter of our unique subconscious.
  • Whatever your reality is, is the reality of your subconscious. You do not become what you think, you become what you believe, and all beliefs are stored in the subconscious.
  • We want what is in our subconscious to be in line with the person we want to be- most of the time it is not.

Neuroplasticity is a new scientific discovery proving that we can literally change our brains through our thoughts and choices. We can physically create new neural pathways and destroy old ones. We can wire out toxic beliefs, experiences, and thinking patterns and wire in truths, good habits, and outstanding thinking patterns.

Neurogenesis means the creation of new brain cells. Each morning we have new cells that are waiting to be programmed to do whatever we are thinking about! This is why it is so important to start your day filled with positive thoughts, truths, scripture, and vision.

Each thought we think is a physical structure in our brain. The more we think about something, the more that structure grows. We have the power to choose what we think about and therefore what neural pathways will be in our brain- which shape the way we see reality.

2. Thoughts change your genes and body: Epigenetics

Dr. Caroline Leaf explains: “Rest in the assurance that what God has enabled you to do with your mind is more powerful and effective than any medication, any threat, any sickness, or any neurological challenge.”

“Research shows that 75-98% of all mental, physical, and behavioral illness is caused by our thoughts life.”

Every thought we think changes and is shaping our DNA. We have countless variations of genes that can switch on or off depending on our thoughts and lifestyle. Toxic thoughts switch off DNA codes that lead to healing and turn on genes you have that may be predisposed to a disease or illness. Positive thoughts switch on genes that heal and that override any ‘bad genes’ you may have.

Our genetic make-up is fluctuating by the minute based on what we are thinking and choosing. Toxic thoughts act as a signal that interrupts normal gene expression, keeping you healthy.

Epigenetics is a new scientific discovery proving that we can change our genetic expression. Our thoughts and our lifestyle control how our genes express themselves. Even if you have a ‘bad’ gene or predisposition for something, your choices determine if that gene gets expressed or not!

3. Observation: Choice and free will

We cannot control the events and circumstances of life, but we can control our reaction, and that reaction changes our brain, controls our genes, and determines our health.

He has given us a prefrontal cortex (which no other mammal has) which allows us the incredible ability to be able to step outside ourselves and observe our own thinking. It also allows us to take an incoming situation and CHOOSE how we are going to respond through our thoughts and actions. We are in control, most people simply just choose not to use it.

Free will is not an illusion. Our mind can, at any moment, choose to think whatever it wants to.

To stay in a state of health, we must take the toxic thought captive and REPLACE it with truth and the positive.

We can choose to rewire our brain.

We have the power to be able to think and choose and create reality.

4. Intentional Thought and Focus

Caroline Leaf explains that multitasking actually damages the brain. It physically cannot focus on more than one thing at once so when you are multitasking, it is having to switch from one thing to the next very rapidly which results in poor activity in the brain and actually makes you worse at whatever you are trying to do.

We were made to focus. To be putting all of our attention on ONE thing at a time. This allows the full thinking process of the brain to occur, and for you to learn and grow deeply. You also end up getting SO MUCH MORE done when you focus on one thing, finish, and then move on to the next.

God made us to take time each day to put all of our focus on HIM and our life. To think deeply about what is working, what is not working, and what needs to change. These moments of thinking deeply and reflection are one of the most powerful things we can do for our brains and our lives.

When you take time to deeply think and focus on something, you are changing your brain and creating new neural pathways to make that a reality.

Most people are not practiced at NOTICING their own thoughts and therefore just let them run all day long and react to them. It takes practice to be able to stop and notice your thoughts and change them.
Default Mode Network:

When you begin to pray, daydream, spend time in self-reflection, your DEFAULT MODE NETWORK in your brain turns on. The DMN allows creativity to come out, allowing you to see solutions to problems, come up with new ideas, and notice what needs to be changed in your life.

The more time you spend in self-reflection and prayer, the more the DMV gets strengthen which improves brain function, and mental, physical, and spiritual health!

“When you pause your activity and enter into a directed rest, you will emerge far ahead of where you would have been if you just operated within the realms of a shifting, shuffling, limited conscious min. This is what God meant when he said “be still and know that I am God” Psalm 46:10.

Basically, this is scientific proof that when stress, worry, sadness, anger, or any situation that comes your way each day- it is important to stop, breathe, deeply think and self-reflect about what is going on and pray about what you are to do, and let it go.

This time spend in deep thinking, prayer, and meditation allows areas in our brain to open up that allows us to revive insight, direction, and peace. Without this time, our mind will just run and run without seeing any solution.

Relates article: Meditation to hear Godhow prayer changes your brain 

5. How to Rewire Your Mind

Through neuroplasticity, we have the power to wire beliefs, habits, and mindsets into our brain. We also have the ability to wire out toxic thinking, toxic habits, and past traumas.

Your nonconscious is what is running you and your outlook on life. To get ideas into your nonconscious, it takes daily repetition for 2-3 21 day cycles.

If you are wanting to change a thinking pattern you have, or truly believe a concept- you cannot simply think it once, or even 5 days and have it stick. You must think, focus, and act upon it every day for at least 2 months.

“The implanted word will save your soul”. If we want to truly believe what the Bible tells us, we need to meditate on 1 truth every day for at least two months to implant it into our subconscience which will then allow us to truly believe and produce the fruit of what it is saying.

How it works:

  • Ask the Holy Spirit to reveal what toxic thinking pattern you need to get rid of and what truth or mindset you need to wire in.
  • Focus on that one thought and that one only for 21-30 days straight, every single day for 5-10 minutes a day. Do not try to do multiple thoughts at once- it won’t work. It has to be focused and intentional.
  • You will be wiring that toxic thought out as you wire a new truth in at the same time.
  • By doing this, you are creating new neural pathways and destroying old ones so you can have a new “default” way of seeing that issue instead of the toxic way you saw it previously.

What to do Each Day for 21-63 Days:

  • Identify the toxic thought, worry, or emotion. And the mindset or habit you want to pick up.
  • Surrender it over to God- visually picture him taking it from you, you laying it on the cross, throwing it in the fire etc- this activates both parts of the brain and creates new connections.
  • Replace it with a truth and the mindset you desire to have: Identify a truth you want to replace the toxic thought with. So everyday when that toxic thought comes up, you replace it with the person you do want to be and the truth you do want to believe and live from.
  • Journal about what it will be like when you are free from that toxic thought and when you have mastered that habit or mindset.
  • Visualize that new truth growing and crowding out the toxic- this is what actually is happening.
  • Set 3 triggers throughout your day. Some people set alarms on their phones, I personally do this right when I wake up, before lunch, and before bed to make it easy to remember.
  • In these 3 times. Stop whatever you are doing and remind yourself of the mindset you want to pick up, and ask the holy spirit to lead your spirit to make that happen.

The above steps, take 7-10 minutes out of your day to go through- and then throughout the day, whenever that thought comes up, replace it with your truth.

Areas to Wire Out

  • Worry
  • Comparison
  • Criticism: Seeing what you don’t like automatically: about yourself, about the world, about, about your life
  • Orphan spirit: Seeing lack instead of abundance first.
  • Fear: Doing actions out of fear instead of love
  • A traumatic experience

Habits/Mindsets to Wire In

  • Presence/Mindfulness
  • Gratitude
  • Setting intentions each day
  • looking at each situation with a different perception
  • taking each thought captive and replacing toxic ones.
  • Optimism: Seeing what you do like verses what you dont like: about yourself, about the world, about, about your life in everything find things that you like in everyone you talk to and every situation you are in
  • Love and Patience

Health Habits

  • Drinking more water
  • Eating tons of veggies
  • Exercise and movement
  • Daily detoxing strategies

Now, just pick one area you want to wire in, and one area you want to wire out and focus on that and that alone every single day for one month. If it is a bigger goal I sometimes go three months until I feel I really have it down.

Do not be overwhelmed, as long as you take just a short amount of time to work on just your one area each day, you brain will begin to change- and be encouraged that the more you do this, the easier it becomes!

Related article: blocked emotions releasing

Takeaways & Daily Lifestyle

  1. Take 10-60 minutes a day to self-reflect, listen, and evaluate your thinking and life to allow the Default Mode Network to switch on and allow you to see solutions and possibilities to your problems and worries.
  2. Spend as much time as you can intentionally thinking thoughts and listening/reading things that fill your nonconscious with who you want to be. The more you get things into your nonconscious- the more it automatically drives your actions and how you see life.
  3. Take time each day to notice toxic thinking patterns you have and choose 1 thinking pattern to wire out and 1 positive thinking pattern to replace it with.
  4. Focus deeply on one task at a time before moving on to the next.
  5. Practice RESPONDING instead of REACTING. When you get triggered or stressed- practice stopping and CHOOSING your reaction instead of just reacting emotionally. The more you practice this, the more that part of your brain gets strengthen and the better you will be!
  6. Keep shifting your focus throughout the day to what you are grateful for, what you do want to happen, and what you appreciate! First thing when you wake up: Think/write 3 things you are grateful for.

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  • Kathy/holyvacationqueen.com

    really rich info..this is a long term commitment! I do believe we can change our thoughts, and habits. I also like to think of the scripture “take captive every thought to make it obedient to Christ.”..this has helped me enormously. But all your info scientifically is powerful.

  • dhcrew

    This is a great breakdown of the book. I have read 3 books by Dr. Leaf. You almost explain it better than she does! Good job. It’s also a reminder that I need to get back into practicing some of this more intentionally. Thanks!

    • Renewing All Things

      Thanks so much! 🙂

  • Wincey Terry-Bryant

    This was awesome! I agree with @dhcrew:disqus! I have several books & dvds by Dr. Leaf. I appreciate her concepts and love her work but I’m particularly grateful for your delivery. You really simplified everything and made it accessible. Thanks!

    • Renewing All Things

      This made my day! Thanks so much for reaching out, I am so glad you liked it! I am going to be more book reviews in the future as well:)

  • nyasha choga

    Wow… thank you so much, I’m starting my 21 days tomorrow, finally… a solution!! God bless and increase you! when the Paul says the spirit of our minds, I think he was talking about our sub conscience.

    • Renewing All Things

      Thank you so much! And I totally agree 🙂

  • Joanna Retherford

    I have your books and detox app. It does work. I’still been awhile since I used it. I need to make headway a lot quicker than one thought per month. Is there a way to tackle more faster? Please?

  • Cherie Rea

    would you please give some references I am interested to read research on how our conscious and subconscious minds are used percentages thank you Cherie

  • Fred Kanshamba

    This summary is like an entire book on its own. I’ve shared it with my friends and it’s really helpful. I would like to receive more please.

    Keep up the good works. I’m sure Doctor Leaf is impressed aswell ??

    • Megan Kelly

      Thanks so much! I would love to write more about this, thanks for letting me know! That is super helpful! Blessings to you!

  • Cherie

    Thank you so much for this book review. Very good.