Abington, the 22nd of the Twelfth Month, 1737/8 [February 1738]:

This morning early, after five days and nights’ fasting, I was considering the many calumnies which the world or people of the world have cast upon the saints and servants of the living God—my very dear, true, and faithful Friends in Christ, called Quakers—as if they kept slaves, or encouraged and connived at it for their interest, favor, or affection, or some base sinister ends. But it is a mere slander, for they abhor the practice, and dare not touch with it, as verily believing it to be one of the grossest sins and iniquities (with all concomitants) in the whole world. 

Objection: But some may and have objected in my hearing that some, yea many called Quakers [keep slaves]—and their preachers, elders, and chief leaders and rulers, men of renown in the congregation (Numbers 16:1–3) and of great repute in the world. Yea, verily the world loves its own (John 15:18–19).   

Answer: But I answer, they were not all Israel who were called Israel (Romans 9:6–8), but some were apostates, vagabonds, and impostors. And they were some of the worst enemies—the very worst the Hebrews had—and procured their ruin, overthrow, and utter destruction, as is largely set forth in the History of the Wars of the Jews by Josephus, beside what is mentioned in holy scripture plentifully by the holy prophets. 

And so it was amongst the primitive Christians—about the time of the Ten Persecutions—when they got a little ease from the heathen tyrants, the apostate Christians went to the same devilish work of murdering and butchering the true Christians: about their creeds, keeping of Easter and other idols, and about the clause of one substance and two substance, as if the eternal Being could be divided. But especially after Constantine the Roman emperor was converted to the Christian faith, in his zeal he gave such large donations and revenues to the church that it is recorded the same day there was a voice heard from heaven, crying aloud, “This day is poison poured into the church!” which the event soon after verified.

By an ancient observation, “religion brought forth wealth, and the daughter devoured the mother.” It is the very same now. So when the bishops, preachers, and rulers grew rich and high, they centered in pride, idleness, and fullness of bread. Then they went together by the ears with might and main, striving who should be greatest. Then to inventing and setting forth the old, nasty, fulsome, stinking whore’s trumpery or merchandise to sale (Revelation 18:13; 17:5).

And they that would not buy it, or could not receive it, might expect to be sent out of the world by all the tortures that wrath and hell could invent, as they could prevail with kings, rulers, and governors to assist them, by unrighteous laws and edicts. And when the magistrates were such fools as to dance after their call, they embrued whole nations and kingdoms in blood.

These things are largely set forth in Eusebius’s Ecclesiastical History. An excellent, sweet book it is, and I could heartily wish all right-thinking, solid, sober men had one of them, especially all magistrates and rulers of all persuasions. I think I should rejoice to see it reprinted in Pennsylvania, although I were out some pounds toward the charge of it, for the good of mankind, notwithstanding I have one by me. If the folio volume cannot be printed, there is an abridgment extant by William Caton, which has passed several editions, being of a small price and soon read.

I could wish likewise that every such person had one of those sweet, edifying books entitled, The Spirit of Martyrs Revived by Ellis Hooks: a cheap book and soon read, abridged from the three large volumes with variety of collections from scripture and other books, from the beginning of the world till within a few years, concerning persecution and persecutors, with curious remarks. 

Objection: Carried a little further concerning some, that go under the name of Quakers, keeping slaves. 

Answer: I answer with Romans 2:17, 19, 21, 23, 24, 28, 29. He is not a Jew, which is one outwardly; neither is that circumcision, which is outward in the flesh: but he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God.  Courteous and gentle reader, please to read the whole chapter in the fear and love of God, and in the Light of Truth, and thou will find and feel excellent matter in it. As in the following chapter likewise.

Revelation 2:9: I know the blasphemy of them which say they are Jews, and are not, but are of the synagogue of Satan. 
Revelation 3:9: I will make them of the synagogue of Satan, which say they are Jews, and are not, but do lie. 

Philadelphia, the 25th of Twelfth Month, 1737/8 [February 1738]: 

This being the ninth day of my fasting, having taken nothing but a draft of spring water several times a day—and am as well in health as ever since I came to Pennsylvania, which is six years this spring—it lies on my mind to say something concerning extortion, in paying or receiving interest for money, which I have been under exercise about a considerable time.

And I could be heartily glad that our Friends as a society would wholly set it aside, although I have something considerable upon interest myself, and nothing else to live on but the labor of my hands, and weakly in body and pretty well in years, being near sixty.