There is no doubt that your thoughts direct the course of your life. We base our actions on what we think in the moment and over longer periods of time.
Thought life is a critical aspect to change of life because what you think or believe about various things will determine how you respond to them. John MacArthur notes:
Thoughts help in forming opinions, creating a belief system and fanning the flame of desires. What we think about determines our emotional mood and leads us to have various feelings. Thoughts take place before emotions and emotions and desires are a result of the thought life. For example: a person who struggles with anxiety thinks open ended thoughts that can begin with a phrase like “what if.” Most often the “what if” has some root in an aspect of reality. The thoughts continue to run along the lines of creating scenarios that are imaginary or merely probable. These thoughts stimulate the body to produce adrenalin and the person then experiences anxiety.
Just as Eve did in the Garden of Eden when she saw that the fruit was pleasing to the eye, we see something that piques interest in us and we begin the thought process of wondering what it would taste like, how it would feel, what it would be like to have it. We experience sudden desire, and desire that smolders over time growing stronger the more we think about the object we want to possess. We then act on our desires or we set them aside permanently or temporarily.
We take in millions of bits of information and weigh it through the thought process, and moral code we have adopted. We conclude that something is true or false, and it then becomes a part of our belief system. Our beliefs stay in place until new information comes along to challenge them. You see, all of their actions, including whatever it was that brought them to counseling began as a thought, belief, or desire in their heart Before a person can change what they habitually do, they must change how they habitually think. Their thoughts and beliefs make up how they “see” sin. If they believe a sin habit is biological or genetic the most they can do is get long-term therapy or take a pill to feel better. The person “sees” their behavior as not being their fault, and believes that they are helpless before impulses, thoughts, and drives.