By early 1636, Bull was working as a weaver in St Botolph without Aldgate, when a complaint was made concerning the "sectaries or schismatiques" of London. The king's commissioners for causes ecclesiastical had been notified that throughout London, and in many other places, "there are at this present [...] sundrie sorts of Separatists and sectaries, as namely Brownists, Anabaptists, Arrians, Thraskists, Famalists, Sensualists, Antinomians, and some other sorts". On 20 February 1636, John Wragg, a messenger of majesty's chamber, was tasked by the commissioners with entering any places where "privat Conventicles or meetings" were suspected and rooting out "seditious and unlawfull writings and papers", utilising "all other his highnes officers ministers and subjects whatsoever" in his search.[1][3] At this time, Bull and Farnham seemed to be members of one such "privat Conventicle" together, as the Puritan author Rose Thurgood, in her "A Lecture of Repentance" records that she "reasoned with my brothers Richard Farnam [sic] & John Bull concerning prayer".[1] Bull and Farnham confronted her and
asked if ever God heard my prayers: yea that hee hath said I to them; For I prayed for my husbands health, and that (I thanke God for his love) hee graunted mee; also I prayed for the life of my Children and that I had; Then I prayed that my husband might amend his life, and so hee was somewhat amended (as I thought) for my praying. The[n] my brothers told mee, that God heard none of my prayers; what none of my prayers (said I to them). Noe none of my prayers, said they to mee; For what you received it was of Gods mercy towards you, and nottfor your praying [...] Then said I to them, you shall never make mee believe that, but God heard my prayers; so home I came, very angry I was with them, to thinke how hott they were against mee for my praying.[4]
According to Naomi Baker, a prominent scholar of Thurgood's work, this position reflected a radical Calvinist belief in the "death of the self", as the agency of individual believers is erased for that of God alone.[5] After her initial outrage at these radical teachings, Thurgood came to accept Farnham and Bull as spiritual advisors, and Baker has speculated on a later personal connection with the two, as Farnham's wife, Elizabeth Addington, has been proposed as the scribe of Thurgood's lecture.[6]
There bee many false reports that goe of mee in the City of London, and I beleeve they are spread abroad in the Countrey. [...] But these things you may report to be truths from my own handwriting: I say, I am one of those two witnesses that are spoken of in the 11 of the Revelation, and that the Lord hath given mee power for the opening and the shutting of the Heavens.
Richard Farnham's testimony in Heywood's True Discourse, taken 16 April 1636.[7]
Bull and Farnham were arrested via Wragg's warrant and examined on 16 April 1636.[1] The year of their arrest, a pamphlet was published by Thomas Heywood, entitled A True Discourse of the Two infamous upstart Prophets (1636), concerning Bull and Farnham, now imprisoned. The pamphlet recorded the "examinations and opinions" of the two, taken on 16 April. Heywood observed Bull was "besotted with the like Lunacy [to Farnham], constantly affirmeth also that he is a Prophet: and one of these two witnesses before spoken of, in all things agreeing with his brother Farnham, and that hee shall also be slaine at Hierusalem where Christ suffered, and shall rise againe." They apparently held that "their prayer [...] can command the clouds to showre downe raine", and that, despite speaking only poor English, they "shall be inspired with the Holy Tongue" at Jerusalem and "be able to speake all Tongues and Languages". Bull and Farnham's tale was apparently widespread enough that Farnham felt the need for his own testimony of his beliefs, dispelling rumours that he had claimed to be the Second Coming of Christ, and instead asserting that he and Bull were the "two witnesses" of Revelation 11:3, who, the Book of Revelation recorded, would "prophesy a thousand two hundred and threescore days, clothed in sackcloth". Heywood was hostile to Bull's prophesies, observing they seemed "to smell of the Sect of the Thraskites and Sabbatarians", and entreating the reader to "pitty their ignorance" and "wondrest at their impudence".[1][2][7]
Bull was imprisoned on 4 May 1636, residing in Bridewell Prison, where Farnham joined him in 1638, after brief stints at Newgate Prison and Bedlam. In 1638, after apparently enduring months of hard labour, he petitioned Archbishop of Canterbury, William Laud to be brought to trial, protesting the "labour of beating hemp, to the afflicting of his weak body, and the being companion of all manner of rogues, to the vexation of his soul", and beseech him that "if he be a false prophet, it is your duty to deal with him as the word of God requires".[1][8] Farnham wrote similar petitions, successively soliciting the help of Archbishop Laud, the Privy Council, and the King of England, Charles I.[1]