“All good books are alike in that they are truer than if they had really happened and after you are finished reading one you will feel that all that happened to you and afterwards it all belongs to you; the good and the bad, the ecstasy, the remorse, and sorrow, the people and the places and how the weather was. If you can get so that you can give that to people, then you are a writer.”

Pt. 2, Ch. 7 - Similar to his remark in "A Letter from Cuba" (1934)
Papa Hemingway (1966)

Variant Do all the good you can, in all the ways you can, to all the souls you can, in every place you can, at all the times you can, with all the zeal you can, as long as ever you can.
In the sermon titled "The Use of Money" Wesley said, "Employ whatever God has entrusted you with in doing good, all possible good, in every possible kind and degree . . . to all men." This sermon is in the collection titled "Wesley's Standard Sermons." They are called "standard" because all Methodist preachers were instructed to read them and use them in interpreting the Christian faith.
Disputed
Variant: Do all the good you can. By all the means you can. In all the ways you can. In all the places you can. At all the times you can. To all the people you can. As long as ever you can.
Source: According to Richard Heitzenrater, Professor of Church History and Wesleyan Studies at Duke Divinity School, there is no evidence that John Wesley ever wrote the rule that is attributed to him.

Source: Echoes at Dawn

Sestina of the Tramp-Royal, Stanza 6.
The Seven Seas (1896)

The Cook, The Thief, His Wife, and Her Lover

Source: The Complete Calvin and Hobbes

"The Witchcraft of Mary-Marie", in Baum's American Fairy Tales (1908)
Short stories
Context: "But what can I do?" cried she, spreading out her arms helplessly. "I can not hew down trees, as my father used; and in all this end of the king's domain there is nothing else to be done. For there are so many shepherds that no more are needed, and so many tillers of the soil that no more can find employment. Ah, I have tried; hut no one wants a weak girl like me."
"Why don't you become a witch?" asked the man.
"Me!" gasped Mary-Marie, amazed. "A witch!"
"Why not?” he inquired, as if surprised.
"Well," said the girl, laughing. "I'm not old enough. Witches, you know, are withered dried-up old hags."
"Oh, not at all!" returned the stranger.
"And they sell their souls to Satan, in return for a knowledge of witchcraft," continued Mary-Marie more seriously.
"Stuff and nonsense!" cried the stranger angrily.
“And all the enjoyment they get in life is riding broomsticks through the air on dark nights," declared the girl.
"Well, well, well!" said the old man in an astonished tone. "One might think you knew all about witches, to hear you chatter. But your words prove you to be very ignorant of the subject. You may find good people and bad people in the world; and so, I suppose, you may find good witches and bad witches. But I must confess most of the witches I have known were very respectable, indeed, and famous for their kind actions."
"Oh. I'd like to be that kind of witch!" said Mary-Marie, clasping her hands earnestly.

Source: 1980s, Trump: The Art of the Deal (1987), p. 60

Source: Love Comes Softly