What the word cult meant began to change in the 1960s when some unusual small religious groups (e.g. the Moonies, etc.) started targeting U.S. high school and college students with aggressive recruiting tactics. Some alarmed families tried engaging the services of professional 'deprogrammers' who would kidnap the young person suspecting of attending a cult, hold them against their will in a motel or other secure site, and attempt to 'talk some sense' into them.
The term cult took on a decidedly negative connotation after tragedies such as the Jonestown massacre of 1978, the 1993 Branch Davidian standoff in Waco, Texas, the California Heaven's Gate group suicide in 1997, and numerous others.
Today many people, including news agencies, are unaware that the term has a very specific and technical meaning when used in religious circles. When employed in such circles it denotes a group that does not accept and teach all the points of a very specific set of doctrinal beliefs some believe are the central tenets of historical Christianity.
For example, almost any group that does not believe and teach that the Godhead is a Trinity is labeled a cult, no matter what sort of recruiting tactics it uses, how benign and serving are its leadership, or how many other doctrines it teaches that agree with orthodox beliefs. Still further, if in an interview by the secular press a prominent religious leader labels a group a cult, the erroneous assumption is that the group is somehow dangerous to the safety of its members and outsiders.
There are three common uses of the term 'cult' in popular society. The first is as a label placed on any religious group that possesses at least one unorthodox doctrine (based on what is considered orthodox at the time). The second is to denote a group that is physically dangerous to outsiders and perhaps even to its own members. The last use is applied to any exclusive group that may use deceptive, abusive, or excessively authoritarian tactics to attract and keep members.
The last use of the term cult is commonly used when the emphasis is sociological or psychological than theological in nature. This is because a group can have very orthodox beliefs by the standards of most Protestant theologians, and yet still be dangerous to the mental, spiritual, and even the physical well-being of its members.
A single charismatic leader or speaker starts, many times, a religious cult. They maintain a very close-knit group of members. They are convinced that THEY and only THEY have the truth. Fear becomes a tool to keep members compliant and to separate them from the outside world. Although they may use Christian terms, in practice they use their own unbiblical versions. Such groups usually do not have any New Age related or occult connections. They also may not have any radical or even violent tendencies.