„Attack the evil that is within yourself, rather than attacking the evil that is in others.“

„We must not only resist, but boldly attack prevailing evils.“

—  John Calvin, book Institutes of the Christian Religion

Prefatory Address, p. 23
Institutes of the Christian Religion (1536; 1559)

„When you see some evil you proceed to immediate action, you make an immediate attack to cure the symptom.“

—  Johann Wolfgang von Goethe German writer, artist, and politician 1749 - 1832

Maxim 598, trans. Stopp
Maxims and Reflections (1833)

„Evil people never believe that they are evil; rather, they believe that everyone else is evil.“

—  Mark Manson American writer and blogger 1984

Source: The Subtle Art of Not Giving a F*ck (2016), Chapter 6, “You’re Wrong About Everything (But So Am I)” (p. 133)

„[Nonviolence] is directed against forces of evil rather than against persons who happen to be doing the evil. It is evil that the nonviolent resister seeks to defeat, not the persons victimized by evil.“

—  Martin Luther King, Jr. American clergyman, activist, and leader in the American Civil Rights Movement 1929 - 1968

Source: Stride Toward Freedom: The Montgomery Story

„I would far rather be ignorant than knowledgeable of evil.“

—  Aeschylus, The Suppliants

Source: The Suppliants, line 453; comparable to "where ignorance is bliss, / 'Tis folly to be wise", Thomas Gray, On a Distant Prospect of Eton College, stanza 10

„Evil must not be countered with another evil but, rather, repelled by an act of goodness.“

—  Mohammed Alkobaisi Iraqi Islamic scholar 1970

Understanding Islam, "Morals and Ethics" http://vod.dmi.ae/media/96716/Ep_03_Morals_and_Ethics Dubai Media

„Fear of evil is greater than the evil itself.“

—  Niccolo Machiavelli Italian politician, Writer and Author 1469 - 1527

Sono maggiori li spaventi ch'e mali.
Act III, scene xi
The Mandrake (1524)

„A maxim for the twenty-first century might well be to start not by fighting evil in the name of good, but by attacking the certainties of people who claim always to know where good and evil are to be found. We should struggle not against the devil himself but what allows the devil to live — Manichaean thinking itself.“

—  Tzvetan Todorov Bulgarian historian, philosopher, structuralist literary critic, sociologist and essayist 1939 - 2017

paraphrased variant:
We should not be simply fighting evil in the name of good, but struggling against the certainties of people who claim always to know where good and evil are to be found.
Source: Hope and Memory: Reflections on the Twentieth Century (2003), Ch. 5 : The Past in the Present, p. 195

„More evil gets done in the name of righteousness than any other way.“

—  Glen Cook, Dreams of Steel

Source: Dreams of Steel (1990), Chapter 23 (p. 310)
Context: “What do you want, Blade. Why are you doing this?”
He shrugged, an uncharacteristic action. “There are many evils in the world. I guess I’ve chosen one for my personal crusade.”
“Why such a hatred for priests?”
He didn’t shrug. He didn’t give me a straight answer, either. “If each man picks an evil and attacks it relentlessly, how long can evil persist?”
That was an easy one. Forever. More evil gets done in the name of righteousness than any other way. Few villains think they are villains. But I left him his illusion. If he had one. I doubted he did. No more than a sword’s blade does.

„May we not say, perhaps, that the evil man is annihilated because he wished to be annihilated, or that he did not wish strongly enough to eternalize himself because he was evil? May we say that it is not believing in the other life which causes a man to be good, but rather that being good causes him believe in it? And what is being good and being evil? These states belong to the sphere of ethics, not of religion; or rather, does not the doing good though being evil pertain to ethics, and the being good [forgivable] though doing evil, to religion?“

—  Miguel de Unamuno 19th-20th century Spanish writer and philosopher 1864 - 1936

The Tragic Sense of Life (1913), X : Religion, the Mythology of the Beyond and the Apocatastasis

„Resist. Come, you’re tough enough, my lady, aren’t you, if you beg for death rather than inflict evil?“

—  Tanith Lee, book The Castle of Dark

Part 4 “The Witch Hunt” (p. 133)
The Castle of Dark (1978)

„Men loved darkness rather than light, because their deeds were evil. For every one that doeth evil hateth the light, neither cometh to the light, lest his deeds should be reproved.“

—  John the Evangelist author of the Gospel of John; traditionally identified with John the Apostle of Jesus, John of Patmos (author of Revela… 10 - 98

Jesus in John 3:19-20 KJV
Gospel of John
Original: (el) ἠγάπησαν οἱ ἄνθρωποι μᾶλλον τὸ σκότος ἢ τὸ φῶς· ἦν γὰρ αὐτῶν πονηρὰ τὰ ἔργα. πᾶς γὰρ ὁ φαῦλα πράσσων μισεῖ τὸ φῶς καὶ οὐκ ἔρχεται πρὸς τὸ φῶς, ἵνα μὴ ἐλεγχθῇ τὰ ἔργα αὐτοῦ.

„I would rather be a little nobody, then to be a evil somebody.“

—  Abraham Lincoln 16th President of the United States 1809 - 1865

„Let us say, rather, that actors are a necessary evil,“

—  Alfred Hitchcock British filmmaker 1899 - 1980

Regarding his oft-cited quote stating that actors are cattle; as paraphrased and quoted in "Town Called Hollywood: Director Pleads Off Poundage" http://www.mediafire.com/view/ix2ammmxkb3flqx/Screen%20Shot%202018-09-11%20at%2012.56.17%20AM.png by Philip K. Scheuer, in The Los Angeles Times (30 May 1943).
Context: [T]he director passed off the phrase as one of his "Machiavellian quips," not to be taken seriously. "Let us say, rather, that actors are a necessary evil," he cautioned, with a straight face. "As a matter of fact, I couldn't work if I weren't on friendly terms with them; I'll bend over backward every time. Besides, I get into each picture I make, if only for a couple of seconds—so I'm probably a frustrated actor at heart myself."

„This is the first adventure I’ve survived without being kidnapped, attacked, knocked unconscious or possessed by evil spirits. A ripped blouse? Ruined skirt? Bad hair? I’d call this progress. ~Jaime Vegas“

—  Kelley Armstrong, book No Humans Involved

Source: No Humans Involved

„Most "necessary evils" are far more evil than necessary.“

—  Richard Branson English business magnate, investor and philanthropist 1950

Source: Losing My Virginity: How I've Survived, Had Fun, and Made a Fortune Doing Business My Way

„Philosophy has taught me to rely on my own convictions rather than on the judgements of others and to concern myself less with whether I am well thought of than whether what I do or say is evil.“

—  Giovanni Pico della Mirandola, book Oration on the Dignity of Man

25. 160; translation by A. Robert Caponigri
Oration on the Dignity of Man (1496)
Original: (la) Docuit me ipsa philosophia a propria potius conscientia quam ab externis pendere iuditiis, cogitareque semper, non tam ne male audiam, quam ne quid male vel dicam ipse vel agam.

„Suffering willingly endured is stronger than evil, it spells death to evil.“

—  Dietrich Bonhoeffer German Lutheran pastor, theologian, dissident anti-Nazi 1906 - 1945

Source: Discipleship (1937), Revenge, p. 142.
Context: Jesus bluntly calls the evil person evil. If I am assailed, I am not to condone or justify aggression. Patient endurance of evil does not mean a recognition of its rights. That is sheer sentimentality, and Jesus will have nothing to do with it. The shameful assault, the deed of violence and the act of exploitation are still evil. … The very fact that the evil which assaults him is unjustifiable makes it imperative that he should not resist it, but play it out and overcome it by patiently enduring the evil person. Suffering willingly endured is stronger than evil, it spells death to evil.

„God does not create pure evil. Rather, in everything that He creates is a wise purpose by virtue of what is good. However, there may be some evil in it for some people, and this is partial, relative evil. As for total evil or absolute evil, the Lord is exonerated of that.“

—  Ibn Taymiyyah Sunni Islamic scholar and theologian, who lived during the era of the first Mamluks (1250-1328) 1263 - 1328

Ibn Taymiyyah, A. (2004) Majmu’ al-Fatawa. Vol 14, p. 266.