Here’s the argument in outline:

1. Our thoughts determine our lives.
2. Our thought patterns (habits of thinking) predominate over one-time thoughts, or thoughts that still take effort to think, because habits are effortless.
3. To make a life change, we must make a thought change.
4. To make a lasting life change, we must make a lasting thought change, i.e., form new habits not just one-time thoughts.
5. The best way to take control over a thought is brute force. The best way to form new mental habits, however, is to read a book or listen to a podcast or hear a speaker… to “outsource” the thinking effort to that other source, over and over, until you internalize it.
6. In this way, your books determine your life! (And Podcasts too)

Some comments on each point:

1. Our thoughts determine our lives.

Not in a particularly mysterious or magical way, but as a simple matter of cause and effect.

Your thoughts are the first step (the first step in your control at least) in a long chain of cause-effect events that result, over time, in the panorama of your life: your emotional state, your level of wisdom and knowledge, the quality of your relationships, your possessions or lack thereof, your living situation, job, hobbies, entertainment consumption, food and diet and exercise habits, sleep habits, and so on.

The way it works is this: what you think about, you (eventually) do something to bring about in your life. Bob is in his current profession because he studied people in that profession, studied that profession, contemplated it, thought about it, for months or perhaps years and thus brought it about that he eventually became a member of that profession. Anne has her current weight, clothing style, level of health, etc., because she thinks certain thoughts over and over about how she wants (or doesn’t want) to look and feel.

2. Our thought patterns (habits of thinking) predominate over one-time thoughts, or thoughts that still take effort to think, because habits are effortless.

Successful people think about what they want and how to get it, most of the time. – Brian Tracy

Naturally, one thought doesn’t necessarily make a huge difference. (Some do.)

But habits or patterns of thought that recur in our minds tens, or even hundreds, of times per day, have a firm and sometimes invisible impact on our actions, feelings, and relationships.

Repeating a phrase hundreds of times is usually referred to as ‘meditating.’ But we are all meditators. The difference is some of us have chosen our mantra, and others have them formed into us by our parents and society.

Once formed, at a young age, habits are self-activating.

Our habits are largely formed (i.e., in childhood) before we are aware and self-conscious that we have thought patterns (i.e., as teens). By this time, they are virtually effortless. They operate on their own steam.

3. To make a life change, we must make a thought change.

Taking responsibility for our thoughts is the first step in taking responsibility for our lives.

For example, the recurring self-critical thought, “I’m not good enough”, playing on repeat hundreds of times a day, can lead a person to try and prove themself over and over, to the exhaustion of himself and the annoyance of those around him who either already believe in him (making the ongoing “proof” unnecessary) or don’t believe in him (making the “proof” appear desparate and tone-deaf).

Noticing this thought, and firmly committing to counter it with a thought like, “I’m not the greatest, but I’m not bad either. I am who I am, by God’s grace” is the beginning of radical transformation.

4. To make a lasting life change, we must make a lasting thought change, i.e., form new habits not just one-time thoughts.

Countering the negative thought every time the initial self-critical thought occurs means that we must be vigilant, alert, awake, aware, and on guard. Successfully countering a negative thought a few times will be a relief to the psyche. But doing so every time (after many weeks or months of practice) will transform the self.

5. The best way to take control over a thought is brute force. The best way to form new mental habits, however, is to read a book or listen to a podcast or hear a speaker… to “outsource” the thinking effort to that other source, over and over, until you internalize it.

The question then becomes, which thoughts to counter? And what to counter them with? This is where outside sources come in.

Reading a book automatically replaces my own train of thought (originating within my own heart) with the train of thought of another (originating in the book).

For “book” you treat it as a variable and can replace it with podcast, lecture, song, conversation, internet article, etc.

By reading books, I can not only learn how and whether to replace my negative thoughts with positive ones, I can more scientifically and surgically decide which thoughts bear replacing and redirecting and what exact thoughts should take their place.

For example, “I’ll just play one more game” or “I’ll just read one more page” or “I’ll just watch one more video” are thoughts that have lost me – in aggregate – thousands of hours of sleep (1-4 hours of lost sleep, times thousands of nights I’ve done this to myself). It took me a long time to realize the source of my suffering the next day: lack of sleep caused: lateness to work, groggy, careless, grumpy, overeating, negative. After realizing the source of all this unhappiness was my lack of sleep, and the source of my lack of sleep was the tempting thought “just one more”, I began to counter this thought. But with what!?

I found a podcast that deals with addictive behaviors that helped me understand. Now, I simply think, “I feel sleepy. I’ll lay down and listen to a story.” I can listen to a story. I can even listen to this podcast at night, in bed, instead of engaging in addictive behaviors, and thus losing sleep.

I’ve begun listening to the Philokalia. By reading about the amazingly pure and humble lives and hearts of 20 or more saint-authors, I am hoping to purify and humble my own heart. Even when I don’t succeed in this, the constant contemplation of their words and the prayers they recommend are an investment in future growth.

6. In this way, your books determine your life! (And Podcasts too)

So the practical conclusion is this: pick up a book like the the Holy Scriptures, Philokalia, the Lives of the Saints, the Way of the Pilgrim (Orthodox), or Practicing the Presence of God and Imitation of Christ (Catholic) or Whole Duty of Man and Fairie Queen (Protestant) and let them start the chain reaction today, resulting (over time) in increased communion with God. (Advanced step: read one of each of the above, and notice/compare the difference in your thoughts and the difference in your life, to help you decide where to invest more time reading and hence letting yourself be formed.)