(Self-examination or self-evaluation is a necessary practice for spiritual progress. The following article speaks of the need for this practice from a Jewish — especially Hasidic — perspective.
The Rebbe speaks against “self-love.” He’s not speaking about healthy self-esteem. By “self-love,” he means: placing the satisfying of our own needs above any other consideration or person, especially in materialistic areas.
How typical this can be of American culture today!
The Rebbe tells us that the main tool in moderating or overcoming this self-love is continuous self-examination.)
Man’s Self-Examination and Preparation
(From the writings of Rabbi Yosef Yitzchak of Lubavitch [1880-1950]; 
translated by Eliezer Danzinger
Published and copyrighted by Kehot Publication Society)
“Any person desiring a life of [productive] labor [or achievement] must set his mind and heart to examine himself in every aspect of his ethical life, as man’s greatest enemy is his inborn self-love, a love that is unbridled, materialistic, dense and coarse.
Self-love is one of the evil inclination’s tools.
It blinds man’s intelligence, dulls his heart, closes his eyes, and plugs up his ears, preventing him from perceiving his shortcomings and the errors of his sins.
Being that man’s path, in his own eyes, is upright, his sins and transgressions – even his inherent basic humaneness — are obscured by this self-love.
This self-love transforms a fool and one devoid of under standing into a person of stature in his own eyes; a dullard into an genius, an arrogant person into a humble person, an ugly person into a handsome one, a cruel individual into an individual of sterling traits, an envious person into a magnanimous one, and so on.
What folly and blindness it is for the fool to mock the stupid, the dense person to ridicule the ignoramus, the arrogant to deride the haughty, the ugly to belittle the filthy and likewise with regard to other moral blemishes — neglecting completely to consider their own blemishes!
Even when these individuals are made aware of their failings, they find hundreds of excuses and recondite reasons for every flaw and deficiency, concluding that the person who brought the matter to their attention was mistaken in thinking of it as a flaw and fault.
Among these people are some whose shortcomings are blatant and whose offenses are unbounded. Yet these blemished individuals sin against the chosen of G‑d’s creatures, man, and against their very own souls by placing themselves, with unconstrained audacity and impudence, upon a pedestal beyond the reach of self- examination.
Woe to these individuals!
They betray the Divine purpose of their souls’ descent from exalted heights to the nadir of depths in this world, [this descent being] in order to acquire fine [refined] character traits — in addition to their study of Torah and the fulfillment of its commandments.
And they forfeit thereby the spiritual excellencies they could have achieved and the concomitant reward in the World to Come. Moreover, they remain disgraced and forever repugnant.
The blame for all this rests completely with this inborn self- love.
As an ox being led to slaughter is the man who fails to examine himself.
Instead [of engaging in critical self-examination], he naively follows his self-love, thereby undermining, Heaven forfend, his ethical and spiritual life, and his raison d’etre.
Man’s life in this world involves a fierce battle between good and evil, truth and falsehood, beauty and repugnancy.
In times of war, one of the stratagems employed is incisive and systematic inspections. Even one’s loved ones and close friends have to be watched with a keen eye — to ensure that they too are fulfilling their obligations in the campaign to vanquish the enemy.
Understandably, it is crucial to monitor vigilantly and examine intensely the foe himself, especially when the enemy conceals himself in the attire of a loved one, self-love, and deceives the person at his every step.
Therefore, the person who desires a life which is consonant with the mission that Divine Providence has decreed for him — to illuminate the world with the light of Torah and the lamp of mitzvos — and which endows him with the spiritual sustenance necessary to carry out his assigned task, must prepare himself through critical self-examination, scrutinizing his service [to G‑d] and his conduct.” 
[How relevant this is today:
“A single powerful person who is convinced of their own Rightness with no thought of introspection is dangerous. We now have a government full of them.” 
But we should give special consideration to our own personal need for self-evaluation. It’s not just a weapon to use against people we disagree with politically.]