“I call on you not to hate, because hate does not leave space for a person to be fair and it makes you blind and closes all doors of thinking.”

Statement quoted in Prophet Singer: The Voice And Vision of Woody Guthrie (2007) by Mark Allan Jackson. There are a few slight variants of this statement, which seems to have originated in a performance monologue.
Context: I hate a song that makes you think that you are not any good. I hate a song that makes you think that you are just born to lose. Bound to lose. No good to nobody. No good for nothing. Because you are too old or too young or too fat or too slim too ugly or too this or too that. Songs that run you down or poke fun at you on account of your bad luck or hard traveling. … I am out to fight those songs to my very last breath of air and my last drop of blood.
I am out to sing songs that will prove to you that this is your world and that if it has hit you pretty hard and knocked you for a dozen loops, no matter what color, what size you are, how you are built, I am out to sing the songs that make you take pride in yourself and in your work.
And the songs that I sing are made up for the most part by all sorts of folks just about like you. I could hire out to the other side, the big money side, and get several dollars every week just to quit singing my own kind of songs and to sing the kind that knock you down still farther and the ones that poke fun at you even more and the ones that make you think you've not any sense at all. But I decided a long time ago that I'd starve to death before I'd sing any such songs as that. The radio waves and your movies and your jukeboxes and your songbooks are already loaded down and running over with such no good songs as that anyhow.

Source: Me Talk Pretty One Day

Source: Birthday

Variant: I think the hardest thing in life is to forgive. Hate is self destructive. If you hate somebody, you're not hurting the person you hate, you're hurting yourself. It's healing, actually, it's real healing...
Forgiveness.

Source: City of Heavenly Fire

Source: Caught

As quoted in The Volta Review (1934), p. 574 http://books.google.de/books?id=qWE4AQAAIAAJ&q=hate, Clifton Fadiman: The American Treasury 1455-1955 (New York 1955) p. 997 http://books.google.de/books?id=PEQ4AAAAIAAJ&q=really+make+them and Hugh Rawson, Margaret Miner: The Oxford Dictionary of American Quotations (2006) p. 431 #5 http://books.google.de/books?id=whg05Z4Nwo0C&pg=PA431&dq=mehitabel from archy and mehitabel (1927)
Variant: If you make people think they're thinking, they'll love you; but if you really make them think, they'll hate you.

As quoted in The Volta Review (1934), p. 574 http://books.google.de/books?id=qWE4AQAAIAAJ&q=hate, Clifton Fadiman: The American Treasury 1455-1955 (New York 1955) p. 997 http://books.google.de/books?id=PEQ4AAAAIAAJ&q=really+make+them and Hugh Rawson, Margaret Miner: The Oxford Dictionary of American Quotations (2006) p. 431 #5 http://books.google.de/books?id=whg05Z4Nwo0C&pg=PA431&dq=mehitabel from archy and mehitabel (1927)

1950s, Loving Your Enemies (Christmas 1957)
Context: Another reason why we must love our enemies is that hate scars the soul and distorts the personality. Mindful that hate is an evil and dangerous force, we too often think of what it does to the person hated. This is understandable, for hate bring irreparable damage to its victims. We have seen its ugly consequences in the ignominious deaths brought to six million Jews by a hate-obsessed madman named Hitler, in the unspeakable violence inflicted upon Negroes by blood-thirsty mobs, in the dark horrors of war, and in the terrible indignities and injustices perpetrated against millions of God's children by unconscionable oppressors.
But there is another side which we must never overlook. Hate is just as injurious to the person who hates. Like an unchecked cancer, hate corrodes the personality and eats away its vital unity. Hate destroys a man's sense of values and his objectivity. It causes him to describe the beautiful as ugly and the ugly as beautiful, and to confuse the true with the false and the false with the true.