Chapter ten of the Tanya defines the difference between two kinds of righteous people, and the gap between them is enormous.
The "completely righteous" person, the tzaddik (a righteous person) gamur (צדיק גמור), has converted all evil within himself into actual good. He does not merely suppress his dark impulses. He has transformed them. The desires that once pulled him toward worldly pleasure now pull him toward God with equal intensity. He has, in the Tanya's language, "completely divested himself of the filthy garments." He looks at physical pleasures and feels nothing but revulsion, because his love of God is so overwhelming that everything else tastes like ash.
The "incompletely righteous" person, the tzaddik she'eino gamur (צדיק שאינו גמור), has fought the same war but not finished it. He has expelled evil from his heart and subdued it. He believes it is gone. But the Tanya says: if it were truly gone, it would have been converted into good. The fact that it was merely expelled, not transformed, means a residue remains. The incompletely righteous person still carries a trace of attraction to worldly things, so small he is not even aware of it.
Rabbi Schneur Zalman explains the mechanism. Complete righteousness requires absolute hatred of evil, "I hate them with the utmost hatred; I regard them as my own enemies" (Psalms 139:22). This hatred must be proportional to love of God. If your love of God is infinite, your hatred of evil will be absolute, and the evil will be fully transformed. If your love is great but not infinite, some sliver of tolerance for worldly pleasure will remain.
The practical implication is both humbling and clarifying. Most people who consider themselves righteous are, at best, incompletely righteous. They have won the war but not destroyed the enemy. The enemy is in hiding, dormant, forgotten. But not dead. The Tanya does not consider this a failure. It considers it reality. Only the rarest souls achieve total transformation. For everyone else, the war continues underground.
Behold, when a person fortifies his divine soul and wages war against his animal soul to such an extent that he expels and eradicates its evil from the left part—as is written, “And you shall root out the evil from within you”1 Deuteronomy 21:21.—yet the evil is not actually converted to goodness, he is called “incompletely righteous” or “a righteous man who suffers.”2 צדיק ורע לו—see ch. 1, n. 7. That is to say, there still lingers in him a fragment of wickedness in the left part, except that it is subjugated and nullified by the good, because of the former’s minuteness. Hence he imagines that he has driven it out and it has quite disappeared. In truth, however, had all the evil in him entirely departed and disappeared, it would have been converted into actual goodness. The explanation of the matter is that “a completely righteous man,” in whom the evil has been converted to goodness and who is consequently called “a righteous man who prospers,”3 צדיק וטוב לו—i.e., “possessing (only) good.” has completely divested himself of the filthy garments of evil. That is to say, he utterly despises the pleasures of this world, finding no enjoyment in human pleasures of merely gratifying the physical appetites instead of [seeking] the service of G–d, inasmuch as they are derived from and originate in the kelipah and sitra achara, for whatever is of the sitra achara is hated by the perfectly righteous man with an absolute hatred, by reason of his great love of G–d and of His holiness with profuse affection and delight and superlative devotion, as is stated above.4 Ch. 9. For they are antithetical one to the other. Thus it is written, “I hate them with the utmost hatred; I regard them as my own enemies. Search me, [L–rd,] and know my heart….”5 Psalms 139:22, 23. Hence, according to the abundance of the love toward G–d, so is the extent of the hatred toward the sitra achara and the utter contempt of evil, for contempt is as much the opposite of real love as is hatred. The “incompletely righteous” is he who does not hate the sitra achara with an absolute hatred; therefore he does not also absolutely abhor evil. And as long as the hatred and scorn of evil are not absolute, there must remain some vestige of love and pleasure in it, and the fouled garments have not entirely and absolutely been shed; therefore the evil has not actually been converted to goodness, since it still has some hold in the filthy garments, except that it is nullified because of its minute quantity and is accounted as nothing. Therefore such a person is called a righteous man, in whom the evil is subjugated and surrendered to him. Accordingly, his love of G–d is also not perfect, with the result that he is called “incompletely righteous.” Now, this grade is subdivided into myriads of degrees in respect of the quality of the minute evil remaining [in him] from any of the four evil elements, as well as in relation to its proportionate abnegation by reason of its minuteness, such as, by way of example, one in sixty, or in a thousand, or in ten thousand, and the like.6 In halachah, in cases of a mixture of a nonkosher element into kosher articles of human consumption (solids or liquids), the nonkosher element is deemed nonexistent if its proportion is less than 1/60th, 1/100th, etc., as the case may be. Cf., e.g., Chullin 97b ff. Such are the gradations of the numerous righteous men who are to be found in every generation, as mentioned in the Gemara, viz., “Eighteen thousand righteous men stand before the Holy One, blessed is He.”7 Sukkah 45b; Sanhedrin 97b. However, it is with regard to the superior quality of the “completely righteous” that Rabbi Shimon bar Yochai said, “I have seen superior men (benei aliyah), and their numbers are few….”8 Ibid. The reason for their title of “superior men”9 Literally, “men of ascent”—בני עליה. is that they convert evil and make it ascend to holiness, as is written in the Zohar in the Introduction,10 Zohar I:4a. that when Rabbi Chiya wished to ascend to the hechal (heavenly shrine) of Rabbi Shimon bar Yochai, he heard a voice come out and say, “Which of you, before coming here, has converted darkness into light and bitter taste into sweetness? [Otherwise] do not approach here,” and so forth. A further explanation of the title “superior men” is that their service in the category of “do good,” in the fulfillment of the Torah and its commandments, is for the sake of the Above, the ultimate of the highest degrees, and not merely in order to attach themselves to G–d so as to quench the thirst of their [own] soul, which thirsts for G–d, as is written, “Ho! All who thirst, go to water,”11 Isaiah 55:1. as is explained elsewhere. Rather [their service is,] as explained in Tikkunei Zohar, “Who is kind?—He who conducts himself with benevolence toward his Creator—toward His nest,12 This homily is based on a play on the words חסיד־חסד, קונו־קנו. The text reads: איזהו חסיד המתחסד עם קונו — עם קן דיליה, לייחדא קודשא בריך הוא ושכינתיה בתחתונים. uniting the Holy One, blessed is He, and His Shechinah within those who dwell in the nethermost worlds.”13 Tikkunei Zohar, Introduction 1b. Cf. Zohar II:114b; III:222b; 281a. As also explained in Raaya Mehemna on Parashat Teitzei, “In the manner of a son who ingratiates himself with his father and mother, whom he loves more than his own body and soul…and is prepared to sacrifice his own life for them, to redeem them…,”14 Zohar III:281a. and as is explained elsewhere.15 The absolute altruistic worshipper is not motivated by a desire to save his soul, or to gratify its longing for unity with the Deity, but by pure love and a desire to please G–d and make His presence felt everywhere. [And both interpretations are complementary, for through acts of refinement of the good out of the nogah, one elevates the “feminine waters,”16 “Male” and “female” are terms used in Kabbalah to denote “giver” and “recipient,” respectively. “Feminine waters” therefore denotes benevolent acts, self-inspired, rising from man to G–d, while “masculine waters” denotes the flow of Divine influence and grace from G–d to man. causing “supernal unions” to bring down the “masculine waters”17 See previous note. which are the flow of [Divine] kindness contained in each of the 248 positive precepts, all of which are in the nature of kindness and “masculine waters,” that is to say, the flow of holiness of His G–dliness, blessed be He, from above downward, to be clothed in those who live in the lower worlds, as explained elsewhere.]