Hazim explores the psychological dynamics by which member of contemporary groups are made willing to perform violent acts:
For those who pursue the American dream it is hard to grasp the idea of following a charismatic figure to the death; yet, some willingly flock to alternative visions. There are reasons for this servile behavior, and the profiles of the docile sheep are consistent. They find rewards to servility, and the motivations vary from person to person. For some it's the promise of the hereafter, for others it's the tangible rewards in this life. Some unfortunate souls have little choice because they are born into such groups or sold to them. Competent, successful people join as well to escape from freedom due to the painful reminders of the poor choices they have made in life, now preferring to forgo decision-making altogether. This is the list of folks authoritarian non state movements can draw from and they know "the harvest is ripe."
Seventeenth Century England also witnessed radical Protestant sects that could be violent. One such sect was the Fifth Monarchy Men. Discussing the Fifth Monarchists, Wikipedia states:
These were not political parties as that term is understood today, but groups clustered around one or more beliefs, some of the believers attaching themselves to more than one group. Although the pre-war establishment had been split by the Civil War, both of the opposing main factions regarded all radical groups as agitators for change, and they are described as such in the Historical Collections of John Rushworth that document events of the early period, and by the Journals of the House of Commons which cover the period of the Republic itself.
Thomas, in Religion and The Decline of Magic,
discusses how English society, from mid-16th to mid-17th Century, from Henry VIII's Reformation to Charles II's Restoration, underwent enormous stress. People responded variously to this stress, from alcholism to magic ritual to witch hunts. One such response was to join these radical Protestant sects.
Hazim's post suggests that today's America likewise is undergoing such stress; so people likewise are joining radical sects.