In the early 17th century, Helwys was the principal formulator of a demand that the church and the state be kept separate in matters of law, so that individuals might have a freedom of religious conscience.
[1] During this time, the Helwyses' home became a haven for radical Puritans (Dissenters within the Church of England), and it is likely that Helwys contributed financially to their mission.
In 1606, when Archbishop Richard Bancroft was forcing ministers to submit to the Book of Common Prayer, Helwys took part in conference of radical Puritans in Coventry discussing whether to quit the Church of England and become Brownists.
Between 1607 and 1608, Helwys, Smyth, Robinson and many others from the Gainsborough and Scrooby congregations fled to the safety of Amsterdam in the more tolerant Dutch Republic.
[6] Later that year, the group led by Smyth and Helwys started renting a meeting house from Dutch Mennonites and were persuaded by them to abandon the doctrine of predestination.
[5] In the next twelve months or so, Helwys wrote three important works: an argument for Arminianism (A Short and Plain Proof, By the Word and Works of God, That God's Decree Is Not the Cause of Any Man's Sin or Condemnation: And That All Men Are Redeemed by Christ; As Also That No Infants Are Condemned), a polemic explaining his differences with the Mennonites (An Advertisement or Admonition to the Congregations, which Men Call the New Fryelers, in the Lowe Countries), and, most importantly, A Short Declaration on the Mistery of Iniquity [sic].
The book also argued that Separatist leaders such as Smyth and Robinson had been wrong to take their churches overseas to escape persecution and that they should return to England.
The historian of Separatism, Stephen Tomkins, describes The Mistery of Iniquity as the most radical and outspoken book of the age and "the most far-reaching declaration of universal religious freedom yet seen in English", but adds: "It is a pity that this most ground-breaking treatise of the Separatist movement should also be its most mean-spirited.
[10] They brought The Mistery of Iniquity with them, and one copy of it was delivered to King James, with a handwritten inscription arguing for liberty of conscience.
Broxtowe Hall, the Helwys' family home, is now only a remnant, but in nearby Bilborough Baptist Church there is a simple plaque to his memory.