Short answers, pulled from the story.
A new religious movement, also called a new religion or modern religion, is a religious or spiritual group with modern origins that sits at the periphery of its society's dominant religious culture. Scholars estimate these movements number in the tens of thousands worldwide. Most have only a few members, while a few have more than a million.
There is no agreed-upon starting point. Some scholars treat the 1950s or the end of the Second World War in 1945 as the defining time, while others reach back to the founding of the Latter Day Saint movement in 1830 and of Tenrikyo in 1838.
In the 1930s, Christian critics began referring to new religious movements as "cults". Since at least the early 2000s, most sociologists of religion have avoided the term because of its pejorative undertones. Scholars such as Eileen Barker and James T. Richardson advocated dropping its use in academia.
Violent incidents involving new religious movements are very rare. The events with the most casualties, such as the 913 deaths at Jonestown beginning in 1978 and the 39 Heaven's Gate suicides in 1997, were all led by a charismatic leader.
A distinct field of new religion studies developed within the academic study of religion in the 1970s. It draws on anthropology, psychiatry, history, psychology, sociology, religious studies, and theology, with sociology playing a particularly prominent early role.
In 2006, J. Gordon Melton, executive director of the Institute for the Study of American Religions at the University of California, Santa Barbara, told The New York Times that 40 to 45 new religious movements emerge each year in the United States.