Whether in coarse or subtle form, these faults exist in each individual according to his own level of service. Some are so indiscernible that one is not conscious of them; they are hidden in his soul nonetheless. He may think that these concerns are not at all relevant to him, though in reality they are. Such a state of affairs is more injurious that any single character trait that stems from the “Other Side” [the forces of evil]. Any particular [blemish] is not as powerful [and corrupting] as a pervasive evil, nor will it necessarily lead to another negative character trait. Baseless hatred, on the other hand, is a general fault, comprising the entire realm of evil which is characterized by division and difference. This is the source of all one’s negative character traits and is the antithesis and opponent of the Name Havayah as a whole, as has been mentioned above, and as will be further explained in later chapters.

Whoever cares for his soul, therefore, and does not want it to be [immersed] in kelipah and evil, nor does he want to develop a bad character, but rather, [desires] to carry out his task, serving G‑d as he should, refining and improving his natural character traits, he ought to examine himself carefully. He should search1 time and again, using the light of a lamp “the2 lamp of G‑d is the soul of man” in every nook and cranny, for all vestiges of this evil (for it will prevent him from truly serving G‑d and refining and elevating his nature). [When] this evil is utterly destroyed, he can proceed securely on his way in the service of prayer with bittul , thus refining his character and fulfilling Torah and mitzvos in the proper manner.

Summary:
Since baseless hatred is the underlying source for all one’s evil character traits, it must be searched for carefully and utterly destroyed.