לע"נ חיים גבריאל בן ידיד נפשי הרב אהרן חנינא הכהן
[משלי ו, כ"ג]
A Mitzva is like a candle. It takes something material [your body] and transforms it into something spiritual. Torah is light itself. The world is filled with darkness and confusion and the Torah lights it up with understanding and purpose. [See Derech Hashem]
But that is not sufficient. דרך חיים - A path for life, תוכחות מוסר - is rebuke. A person can live his whole life without realizing that he is OFF. Many people have levels of self awareness which leave much to be desired and serve as a barrier to growth. In my life I have heard THOUSANDS of excuses and justifications, but the words "I was so wrong. I am sorry. I must work on myself and make sure that ti doesn't happen again" [probably because "ti" is not a word] are rarely if ever heard. That is why if you observe MOST people they never really change. I have known people for 40 plus years who are the same they were back then. This is because their דרך חיים is not תוכחות מוסר. They are trying to get through life with the maximum amount of pleasure and success [even success in spiritual matters] without ever taking the trouble to really examine who they are, the building blocks of their personality, why they are stuck in certain behaviors, how to change etc. etc. So their marriages are lacking, their relationships are lacking and their general existence and Avodas Hashem are filled with holes and inadequacies. The positives in their lives give enough of a good feeling that people manage but that is not the goal.
The goal is shleimus. To reach shleimus one needs תוכחות מוסר - either internal or from a Rebbi or guide.
People are resistant to change because they are comfortable with what they are used to but we were placed on this earth in order to grow which often means giving up thought processes and behaviors to which we became accustomed.