Chassidic teachings point out that the vast majority of controversy and arguments are based on nothing more than issues of personal self-aggrandizement. A person whose ego begins to dominate his every action looks upon all others as a threat to his very existence. The mere fact that others exist is meant to serve as a constant reminder that one's ego cannot monopolize the world around him. Yet, the egoist looks askance at the rest of the world, looking for deficiencies in others order to deal with his own inferiority complex.
These tragic circumstances underscore the reason for the Torah's unremitting stand against controversy and divided hearts. Controversy is not looked upon as just another sin in a long line of other sins; rather controversy is considered to be the very essence of evil. In fact, the primary difference between the realm of holiness versus that of evil is that in the former unity and self-effacement abound whereas in the latter we find pride, egoism, and division.
The Torah provides an example of this difference when describing Jacob and Esav. Jacob descends to Egypt with his whole family (70 souls) - and the Hebrew word for "souls" is written in the singular form to show that they were all unified. In contrast, Esav's family is referred to as six souls - with the Hebrew word for "souls" in the plural form, indicating their inherent divisiveness.
We find therefore that most controversies are founded upon unwarranted hatred - a hatred based upon no defined reason other than a feeling that our fellow man somehow represents a threat to the existence of our ego. That which characterizes the strength and seeming validity of the controversy is neither the personal makeup of our fellow man nor his deeds, but rather the measure of our ego.
To the extent that we appear great in our own estimation, so does our fellow man get in our way. We'll publicize our "opponent's" weaknesses and minimize his good traits and in so doing find a hundred and one reasons for pursuing him and dragging him down. Somehow the main reason gets lost in the show-down; this other fellow someone manages to arouse in us a gut reaction revealing a "there's-no-one-else-but-me" attitude.
Even a serious problem can be dealt with properly with enough personal attention. However, when the very essence of the person is the cause for controversy, it is necessary to subdue their proud ego.
This is the reason for the fact that overcoming the evil of controversies is so difficult. Many good and well-meaning individuals have succumbed to controversy, even at the expense of great personal loss and against the backdrop of no solid rational basis. This is all due to the fact that controversies embody the epitome of evil.
Only in the Time to Come, when G-d will dispel all evil from the face of the earth, will jealousy, competitiveness, division, and controversy cease to exist.