In my opinion, this is true despite all the evil and sin that the world is full of because of this middah of self-love. Added to the challenge of wealth, this middah will cause him to stumble until the depths, as it is written, “Lest I grow full and deny[, and say, 'Who is Hashem?'” (Proverbs 30:9)] Because of the greatness of a person’s attachment to his own qav, if Hashem graced him with wealth, and he believes with complete true faith that everything is the Holy One’s, he is in truth poor. What he has isn’t his. However, if he denies G-d, then it is all his and he is in his own mind truly wealthy. Therefore, to satisfy his desire to enjoy his wealth, he will habituate himself to deny G-d, and then his error is complete. ולדעתי, הנה מלבד כל הרעות והחטאים שהעולם מלא מהם לרגלי מדה זו של אהבת עצמו, הנה גס לנסיון העושר תצטרף מדה זו להכשילו עד התהום כמה שכתב “פן אשבע וכחשתי”, שלרגלי גודל תשוקת האדם בקב שלו, הנה אם חננו ה׳ בעושר ויהיה מאמין באמונת האמת שהכל של הקב״ה הרי הוא עני באמת, ומה שיש לו אינו שלו, אבל אם יכפור בה׳ אז הכל שלו והוא עשיר ממש לפי דעתו, ועל כן למלא תשוקתו לזכות בעשרו, הוא מתרגל לכפור בה׳ ואז ממלא תאותו בשלמות,
Rav Shim’on Shkop holds that self-interest is a central part of Hashem’s plan for man, and so essential that its value outweighs the obvious problems it enables. Before continuing this line of reasoning, Rav Shim’on pauses to reinforce our awareness of those dangers.
Inherent in Hashem making a world in which we can be creative beings in His “Image” is that that world operate with some measure of predictability. Our plans may be thwarted by the unexpected, but the universe must run consistently enough so that we can even engage in making plans to begin with.
Our need to be people requires shoving things not under our control to the mental background, and to focus on what we can improve about the situation we find ourselves in, things we actually have the power to change. In order to be motivated to produce, we need to take pride in that which we produced. To create, we need to love ourselves and what we create.
But pride of accomplishment naturally leads to kafui tovah, ingratitude. That maximizes my sense of accomplishment and thus my pride. A person who is happier with one measure he made himself than with what he received is likely to focus all attention to his own contribution to the result and train himself to ignore what Hashem contributed. And that way leads to apostasy — “and then his error is complete”.