A cult is a term for a religion or community of belief that is regarded as illegitimate, heretical, or far outside mainstream beliefs. Although some consider it to be a statement of opinion, "cult" has well-defined meanings.
Some religions labeled "cults" are dangerous, and in rare but well-publicized cases have proven to be fatal, such as Jim Jones' group in the late 1970s in Guyana (see Jonestown Massacre).
Sect vs. Cult
Strictly speaking, the terms "cult" and "sect" are not synonymous, although some people use the two terms interchangeably. Although many groups consider themselves sects, naturally no group considers itself to be a cult.
Definitions of "cult"
In a general sense, a cult is a group which exercises mind control over its followers.
The word "cult" is not in the Bible but its direct corollary is heresy or heretic. Other Biblical terms are false teachers, false prophets and false brethren.
- They claim to have a new revelation from God.
- They claim to have an exclusive interpretation of Scripture.
- They have a source of authority that supersedes the Bible.
- They have a view of Jesus contrary to biblical teaching.
- They reject orthodox Christianity as having departed from what it should be.
- They say one thing publicly but something different internally.
- They reject or have a distorted view of the trinity.
- They keep changing their teaching.
- They have a strong leader who considers himself the messenger of God.
- They require "works", and never teach that salvation is simply by placing one's faith in Christ.
- They make false prophecies.
In the Catholic Church, 'cult' can also be used to describe a follower's particular devotion to a saint or another aspect of the faith, e.g. the cult of St Mary or of the Holy Cross. This usage does not have the negative connotations of the more common meaning described on this page. It is much less commonly used in the present day to avoid confusion with dangerous cults.
Communist Party as a cult
- Party members were constantly working in the interests of the USSR, and at the dictates of the USSR, while lying to and manipulating their friends and co-workers about their motives. They misrepresented their political positions as independent radical opinions when in reality those positions were dictated from elsewhere. It was a cult. 
There have been cults which have claimed to be Christian, as well as cults which claim some other religious affiliation, or no affiliation at all. One notable example of a cult is the "People's Temple" operated by Jim Jones. Jones' insistence that all his true followers drink poisoned fruit punch led to the deaths of 913 of his converts at their enclave of Jonestown in Guyana. Another example is the cult of Maratreanism.
The process of attempting to "rescue" people from cults, and reverse perceived or actual mind control, is known as deprogramming, and is controversial from both a legal and social perspective.
- Watchman Fellowship (According to ApologeticsIndex, "Considered by many to be the foremost Christian countercult and apologetics ministry")
- Did Scientology Strike Back? Article from June 1997 issue of American Lawyer about Scientology's takeover of the Cult Awareness Network.
- CESNUR Center for Studies on New Religions