The Esrog - Alone

It takes a conscious effort to connect the Esrog to the other three species because oftentimes the Tzaddikim -righteous (who are symbolized by the Esrog) have a tendency to look upon the wicked with a superficial glance and distance and separate from them. They must make sure that they do not separate from the other three species and to join the Esrog with the Lulav and Aravah (which represent those less righteous) so they are literally one.
It is the righteous who are most likely to err when it comes to unity. The forces of evil make every effort to cause them to err as they know that if the righteous would make peace with everyone else and feel unified with the rest of the Jewish Nation, as symbolized by the Lulav, then the Redemption would come immediately. The Yetzer Hora makes every effort to separate the Esrog from the other species and to instill within them thoughts of separation, filled with hubris. G-d forbid that people should fall into this trap because within lies the secret of our Redemption.
א"ת קמ"א

The Breaking

HaChalban quotes Rav Kook:
Why was it necessary for their to be a breaking of the vessels at the time of Creation?
Godliness gives according to its ability, whereas the recipient is limited which results in its receiving a finite amount of goodness. So the good is given in infinite measure, as is its nature, and is unlimited Godliness, despite the fact that the receiving Creation is incapable of receiving such goodness. Creation will completely shatter and then rebuild itself it its desire to return to the unbound source, to unite with God.
In this manner the Creation creates itself to be on a level of completeness akin to its Creator. It rises above the limitations of a Creation which would not have been possible without being exposed to goodness that was beyond its ability to receive. It would have remained on the level of a Creation and never approached that of the Creator...
The World of Tohu, its shattering and rebuilding, teach us that the urge to rectify, improve and exist operates very powerfully. Existence cannot receive the powerful goodness of the Higher Existence, the unlimited power. The limited existence melts before the goodness, the power of life; it shatters because of its great ambition. But that does not prevent the good from continuing on its path. It rebuilds after breakage and the new building is beautiful with immeasurable value. The measure of good is so much greater than that of suffering that it is worth suffering all the pain of shattering, all the ruination of destruction, so that such improved worlds can emerge that carry a richness of life which, left to their own devices, would have been beyond their ability.The Creator does not choose a path that is measured and constricted commensurate with the ability of existence. Were He to do so the good would be limited and not according to the the powerful life-force of the Creator of All, but based on the conditions of the weak Creation.
אלול תשרי ק"ל