No mind of a creature can attain Him. - Yehuda Ashlag

[A]ngels made no complaint about any of the creatures that were created during the six days of Creation, except about Man. This is because he was created in God's image and consists of Upper and Lower together. When the angels saw it, they were startled and bewildered. How would the pure, spiritual soul descend from its sublime degree, and come and dwell in the same abode with this filthy, beastly body? (...) The answer that came to them is is that there is already a tower filled abundantly, and empty of guests. To fill it with guests, we need the existence of this human, made of Upper and lower together (...) Know that this tower, filled abundantly, implies all the pleasure and the goodness for which He has created the creatures.

It is well known to researchers of nature that one cannot perform even the slightest movement without motivation, meaning without somehow benefiting oneself. When, for example, one moves one’s hand from the chair to the table it is because one thinks that by putting one’s hand on the table one will thus receive greater pleasure. If one would not think so, one would leave one's hand on the chair for the rest of one's life without moving it an inch, all the more so concerning greater efforts.

There is a positive force, meaning constructive, and a negative force, meaning negative and destructive. They create and complement the entire reality in general and particular through their harsh and perpetual war with one another. As we have said above, the negative force appears at the end of every political phase, elevating it to a better state, and thus the phases follow one another until they reach their ultimate perfection (...) In addition, being a social creature, the individual development is not enough. Rather, one’s ultimate perfection depends on the development of all the members of society.