We are COMMANDED to LOVE good and to HATE evil

B"H

From here emerges the fundamental contrast between the thinking of G-d and the alien culture of the nations and the assimilationists among our own people.  In G-d's Torah, tolerance toward evil is inappropriate and impossible.  There does not exist any concept of coexistence between good and evil.  Quite the contrary, an oft repeated decree and command is this: "Destroy evil from your midst! Destroy evil from Israel!"  (Deut. 13:6; 17:7,12; 19:19; 21:21-22,24; 24:7).  Time and time again, G-d commands us regarding the need to separate between good and evil, so as to eradicate the evil from our midst.

 Evil is the thing G-d most hates.  It contradicts the purpose of Creation of the world, which is wholly good.  It is an unseemly black mark, marring the beauty and radiance of G-d's perfect, holy, entirely good world.  Evil threatens G-d's kingdom, as it were, and even threatens G-d's presence in that world.  Evil threatens G-d's kingdom, as it were, and even threaten's G-d's presence in that world. It threatens the continued existence of the world, created only for the sake of goodness.

 As King David said (Psalms 119:104),  "From Your precepts I get understanding.  Therefore I hate every false way"; and "I hate them that are of a double mind, but Your law do I love" (Ibid., v. 113); and "I hate and abhor falsehood" (Ibid., v. 163).

Furthermore, Amos said, "Seek good and not evil... Hate the evil and love the good" (Amos 5;14-15). And King Solomon said, "The fear of the L-rd is to hate evil"  (Prov. 8:13).

King David also said (Psalms 5:5), "You are not a G-d Who has pleasure in wickedness.  Evil shall not sojourn with You."  If G-d hates evil, He is also an enemy of evildoers.  As King David continues in the following verse, "The boasters shall not stand in Your sight.  You hate all workers of iniquity." In other words, if "evil shall not sojourn" with G-d, then it is clear that He "hates all workers of iniquity."  He also said, "The face of the L-rd is against them that do evil"  (Ibid., 34:17).

Therefore, wherever the Torah says, "Destroy evil from your midst," Onkelos renders it as, "Destroy evildoers from your midst." Evil, per se, is only an inanimate concept.  Only with the advent of evildoers, who translate evil into the language of reality, bringing it to life, does evil actually enter the world.  Therefore, despite their being His own handiwork, G-d hates them and commands that they be removed from the world.

Just as G-d loves good, so too, man, whose task is to emulate G-d, is obligated to love good and to cling to it and to ensure its spread throughout the world.  Since G-d hates evil and evildoers, it is man's task as well to hate evil and to destroy it.  As King David said (Psalms 97:10), "Ye that love the L-rd, hate evil!"  That is, the duty of those who love G-d is to hate evil and eradicate it from the world.

    Clearly, just as G-d hates evildoers, so must a Jew hate them and frustrate their designs.  As King David said, "I beheld them that were faithless and strove with them, because they observed not Your word" (Psalms 119;158); and "Do I not hate them, O L-rd, those who hate You?  Do I not strive with them that rise up against You?  I hate them with the utmost hatred.  I count them my enemies"  (Ibid., v. 139:21-22).  Redak comments on the phrase "utmost hatred":  "Hatred so great he could not hate them any more."

We also find, "They that forsake the law praise the wicked, but such as keep the law contend with them: (Prov.  28:4).  Metzudat David comments: "Contend with them:  They take issue with their wickedness, and even if the evildoers are great in number, they do not flatter them."  Ibn Ezra suggest a remarkable new idea when he comments, "'Contend with them': with those who forsake the law." Our sages said (Yevamot 103a-b):

Everything that is good when done by the righteous, is evil when done by the wicked:  [G-d told Laban]  "Take heed that you speak not to Jacob either good or bad" (Gen.  31:24).  I might understand his being forbidden to speak evil to him.  Fine!  But why good as well?  The point is that good deeds done by the wicked for the righteous are bad for them.

Moreover, as noted above, Or HaChaim comments on the verse, "You shall consume all the peoples that the L-rd your G-d delivers unto you.  Your eye shall not pity them"  (Deut.  7:16):  This conforms with , "Taking pity on the wicked is cruel' (Prov. 12:10).  In other words, such behavior is not good but evil."

King Solomon said (Prov. 21:12), "The righteous man who brings the evildoer success [such that the evildoer then attributes his success not to G-d but to himself-- Metzudat David] leads him astray to greater evil," and in Shemot Rabbah 9:2 we find:

Say unto Aaron:  "Take your rod"  (Ex. 7;():  This conforms with, "The rod of your strength G-d will send forth out of Zion.  Rule in the midst of your enemies"  (Psalms 110:2).  G-d dominates the wicked only with a rod.  Why?  Because they are likened to dogs.  As it says, "They return at evening.  They howl like a dog"  (Ibid., 59:7).  Just as dogs are commonly smitten with a rod, so are the wicked smitten.  It therefore mentions, "the rod of your strength"... G-d said to them, "Pharaoh is an evildoer.  If he asks you for a miracle, smite him with a rod."

Some agree that we are duty-bound to fight for good and to praise goodness and good people, yet they hold that we should not wage war against evil, and certainly should not provoke or curse the evildoer, yet they are in grave error:

Whoever mentions an evildoer without cursing him misses out on a Torah commandment-- "The name of the wicked shall rot" (Prov.  10:7).  Whenever Rav mentioned Haman on Purim he would say, "Cursed be Haman and cursed be his sons," to fulfill the verse from Proverbs.  (Bereshit Rabbah 49:1)

Here it would be fitting to interpret our sages' words from Megillah 7b:  "A man is required to become so intoxicated on Purim that he does not know the difference between 'Cursed be Haman' and 'Blessed be Mordechai,'" brought down as law in Shulchan Aruch, Orach Chim 695:2.  Many fine people have difficulty understanding this utterance.  I believe our sages established here a powerful and remarkable principle: the point is not that one should drink until he becomes confused and says, "Cursed be Mordechai,"  G-d forbid.  Rather, he should understand that there is no difference between blessing Mordechai and cursing Haman, between blessing the righteous man and cursing the evil one.  Both are mitzvot.  It is a mitzvah to fight and curse the evildoer precisely the way it is a mitzvah to bless the righteous man.  On Purim one should not hesitate to curse and hate Haman, because this is a mitzvah exactly like blessing a righteous man.  The two are equal.  

(Rabbi Meir Kahane, Or HaRa'ayon,pp.126-129)