Why does the Rabbi think the psychological aspect is not essential? I think that perhaps the very fact that the Rabbi sees it that way is itself a psychological matter, since the Rabbi is temperamentally inclined toward rationality. And if the Rabbi personally does not see a need for it, fine—but I think the matter is essential. If the Creator gave the Torah, He gave it to a human being—body and soul. And if there are people who, on the one hand, are rational, but are also looking for an answer for the soul—it is a shame that there isn’t one. We must not forget that the essence is not to investigate, but to observe and serve God. A person investigates reality and reaches the conclusion that there is a Creator who gave the Torah, etc.—what has the Creator ‘gained’ from that? Of course, without investigation there is no basis for us truly to know whom we are serving, whether there even is such a One, and so on. But one could say that precisely the matter of investigation, which the Rabbi deals with so much, is itself a means that enables a commandment—a basic stage of knowing reality. But the psychological aspect is a means for the essence itself, which in the end is not to know but to observe. And the fact is that for most human beings there is really no way to ignore this issue, since it is like one of the laws of nature that we know. And this understanding actually comes from a rational place, from recognizing the human being. More generally, there is often an unjustified disregard for the human soul, as though it were not sufficiently essential or rational. But there is no contradiction between a rational outlook and understanding the basic reality of human nature, the soul; on the contrary, if one does not understand this, something is missing in one’s rational understanding of reality.

Avi, notice that every group in the religious population has a different path to personal connection with observing the commandments. The Lithuanians serve God in one style, and the Hasidim serve God through those same commandments in a different way. Seemingly this supports what Rabbi Michi says—that the style is not essential but cultural. Seemingly, you yourself also see these groups as differing culturally, not essentially.

That said, it may be that you and Rabbi Michi are giving the word “essential” different meanings.
You are demanding authenticity—that is, that observing the commandments be part of one’s personality and not external to it, as Kierkegaard wrote and as every psychologist encourages—and Rabbi Michi is demanding obedience to a divine command, whether it resonates with you or not.

I recently saw in some book something about God and cubes, where he writes that every Jew sees contradictions in the New Testament and every Christian sees duplications in the Hebrew Bible (Tanakh), and likewise everyone sees problems in the other religion’s book. The point is that there are two approaches to everything: do you come from within and with sympathy, or from outside and with criticism? In other words, the emotional connection, or even the identity connection, greatly affects your rationality when reading the book.
If the author of the book were rational to the highest degree, then seemingly there would be no room for these arguments, because every text should be examined purely on whether it is true / sensible / logical or not, and there should be no place for everything around it. Therefore I think the author also understands that there is something more than merely means that enable a commandment, something more essential, also at the point of connecting the person to Torah and religion. A human being was created not only from intellect, but also from emotion and heart. True, this part is more individual, but there is no reason to lower its status just because of that.

Avi and Moshe,
I explained that it is not essential in the sense that there is nothing to say about it. Claims in the field of psychology belong to the question of what is helpful, and that of course varies from person to person. The questions I deal with are what is true, not what is helpful.
Moshe, the fact that many people are biased does not mean that truth is unimportant and that psychology is significant. It only means that it influences many people.