Roger Williams was ordered to be banished from the Massachusetts Bay Colony in 1635, and he fled to Rhode Island. While in London in the 1640s, Williams published his most often cited text, The Bloudy Tenent of Persecution, perhaps more often cited for its lurid title than for its compelling prose. The book was a disorganized mess. Below is a sample of Williams's arguments opposing persecution against conscience.

Roger Williams, The Bloudy Tenent of Persecution, for the Cause of Conscience, Discussed in a Conference Between Truth and Peace. (London, 1644). 

Preface: [Basic Principals of the Book]

First. That the blood of so many hundred thousand souls of protestants and papists, spilt in the wars. of present and former ages, for their respective consciences, is not required nor accepted by Jesus Christ the Prince of Peace.

Secondly. Pregnant scriptures and arguments are throughout the work proposed against the doctrine of persecution for cause of conscience.

Thirdly. Satisfactory answers are given to scriptures and objections produced by Mr. Calvin, Beza, Mr. Cotton, and the ministers of the New English churches, and others former and later, tending to prove the doctrine of persecution for cause of conscience.

Fourthly. The doctrine of persecution for cause of conscience, is proved guilty of all the blood of the souls crying for vengeance under the altar.

Fifthly. All civil states, with their officers of justice, in their respective constitutions and administrations, are proved essentially civil, and therefore not judges, governors, or defenders of the spiritual, or Christian, state and worship.

Sixthly. It is the will and command of God that, since the coming of his Son the Lord Jesus, a permission of the most Paganish, Jewish, Turkish, or anti-christian consciences and worships be granted to all men in all nations and countries: and they are only to be fought against with that sword which is only, in soul matters, able to conquer: to wit, the sword of God's Spirit, the word of God.

Seventhly. The state of the land of Israel, the kings and people thereof, in peace and war, is proved figurative and ceremonial, and no pattern nor precedent for any kingdom or civil state in the world to follow.

Eighthly. God requireth not an uniformity of religion to be enacted and enforced in any civil state; which enforced uniformity, sooner or later, is the greatest occasion of civil war, ravishing of conscience, persecution of Christ Jesus in his servants, and of the hypocrisy and destruction of millions of souls.

Ninthly. In holding an enforced uniformity of religion in a civil state, we must necessarily disclaim our desires and hopes of the Jews' conversion to Christ.

Tenthly. An enforced uniformity of religion throughout a nation or civil state, confounds the civil and religious, denies the principles of Christianity and civility, and that Jesus Christ is come in the flesh.

Eleventhly. The permission of other consciences and worships than a state professeth, only can, according to God, procure a firm and lasting peace; good assurance being taken, according to the wisdom of the civil state, for uniformity of civil obedience from all sorts.

Twelfthly. Lastly, true civility and Christianity may both flourish in a state or kingdom, notwithstanding. the permission of divers and contrary consciences, either of Jew or Gentile.
 
 

To the Right Honorable Both Houses of the High Court of Parliament:

Right Honorable and Renowned Patriots,

Next to saving of your souls in the lamentable shipwreck of mankind, your task as Chrsitans is to save the souls, but as magistrates the bodies and goods, of others. . . .

Two things your honors here may please to view, in this controvsersy of persecution for cause of conscience, beyond what is extant.

First, The whole body of this controversy formed and pitched in true battalia.

Secondly, . . . your Honours shall see the controversy is discussed with men as able as most, eminent for ability and piety -- Mr. Cotton, and the New England ministers. . . .

Right Honourable, soul yoke, soul oppressions, plunderings, ravishings, ?c., are of a crimson and deepest dye., and I believe the chief of England's sins -- unstopping the vials of England's present sorrows. . . .

Thirdly. [That] whatever way of worshipping God your own consciences are persuaded to walk in, yet, from any bloody act of violence to the consciences of others, it may never be told at Rome nor Oxford, that the parliament of England hath committed a greater rape than if they had forced or ravished the bodies of all the women in the world.

Chap. 3:

. . . I acknowledge that to molest any person, Jew or Gentile, for either professing doctrine, or practising worship merely religious or spiritual, it is to persecute him; and such a person, whatever his doctrine or practice be, true or false, suffereth persecution for conscience.

But withal I desire it may be well observed, that this distinction is not full and complete. For beside this, that a man may be persecuted because he holdeth or practiseth what he believes in conscience to be a truth, as Daniel did, for which he was cast into the lions' den, Dan. vi. 16, and many thousands of Christians, because they durst not cease to preach and practise what they believed was by God commanded, as the apostles answered, Acts iv. and v., I say, besides this, a man may also be persecuted because he dares not be constrained to yield obedience to such doctrines and worships as are by men invented and appointed. So the three famous Jews, who were cast into the fiery furnace for refusing to fall down, in a nonconformity, to the whole conforming world, before the golden image, Dan. iii. 21.5 So thousands of Christ's witnesses, and of late in those bloody Marian days, have rather chosen to yield their bodies to all sorts of torments, than to subscribe to doctrines, or practise worships, unto which the states and times (as Nebuchadnezzar to his golden image) have compelled and urged them.

A chaste wife will not only abhor to be restrained from soul in God's worship, like her husband's bed as adulterous and polluted, but also abhor (if not much more) to be constrained to the bed of a stranger. And what is abominable in corporal, is much more loathsome in spiritual whoredom and defilement.

The spouse of Christ Jesus, who could not find her soul's beloved in the ways of his worship and ministry, . . . abhorred to turn aside to other flocks, worships, ?c., and to embrace the bosom of a false Christ. . . .

Chap. 9:

. . . Breech of civil peace may arise when false and idolatrous practices are held forth, and yet no breach of civil peace from the doctrine or practice, or the manner of holding forth, but from that wrong and preposterous way of suppressing, preventing, and extinguishing such doctrines or practices by weapons of wrath and blood, whips, stocks, imprisonment, banishment, death, ?c.; by which men commonly are persuaded to convert heretics, and to cast out unclean spirits, which only the finger of God can do, that is, the mighty power of the Spirit in the word.

Hence the town is in an uproar, and the country takes the alarm to expel that fog or mist of error, heresy, blasphemy, as is supposed, with swords and guns. Whereas it is light alone, even light from the bright shining Sun of Righteousness, which is able, in the souls and consciences of men to dispel and scatter such fogs and darkness.

Chap. 16:

And this is the more carefully to be minded, because whenever a toleration of others' religion and conscience is pleaded for, such as are (I hope in truth) zealous for God, readily produce plenty of scriptures written to the church, both before and since Christ's coming, all commanding and pressing the putting forth of the unclean, the cutting off the obstinate, the purging out the leaven, rejecting of heretics. As if because briars, thorns, and thistles may not be in the garden of the church, therefore they must all be plucked up out of the wilderness. Whereas he that is a briar, that is, a Jew, a Turk, a pagan, an anti-christian, today, may be, when the word of the Lord runs freely, a member of Jesus Christ tomorrow, cut out of the wild olive and planted into the true.

Mr. Cotton's Letter, Lately Printed, Examined and Answered.

. . . After my public trial and answers at the general court, one of the most eminent magistrates, whose name and speech may by others be remembered, stood up and spake:

"Mr. Williams," said he, "holds forth these four particulars:

"First, That we have not our land by patent from the king, but that the natives are the true owners of it, and that we ought to repent of such a receiving it by patent."

"Secondly, That it is not lawful to call a wicked person to swear, [or] to pray, as being actions of God's worship.

"Thirdly, That it is not lawful to hear any of the minsters of the parish assemblies in England

"Fourthly, that the civil magistrate's power extends only to the bodies, and goods, and outward state of men, ?c.

I acknowledge the particulars were rightly summed up, . . . I shall be ready for the same grounds not only to be bound and banished, but to die also in New England, as for most holy truths of God in Christ Jesus.

Source: Roger Williams, The Bloudy Tenent of Persecution, for the Cause of Conscience, Discussed: (1644; reprinted London, 1848), 1-4, 6, 38, 53, 66, 375.