A cult can be defined in a theological sense or a sociological sense. In the theological sense a cult can be defined as a religious organization that claims to be Christian, and may appear to be Christian, but one whose core beliefs are contrary to basic, biblical Christian beliefs. In the sociological sense a cult can be defined as a religious or political organization headed by a leader who dominates his followers, usually with manipulation or mind control. Most cults actually fit both definitions.

Examples of major theological cults include Latter-Day Saints (Mormonism), Jehovah’s Witnesses, Christian Science, the Unification Church, the Theosophical Society, the Children of God, the Way International, the Church of New Jerusalem, Christadelphians, Scientology, "Oneness" Pentecostal Churches (aka. the "Jesus Only" Movement), Unitarian Universalism, the Jesus Seminar, and the International Churches of Christ (not to be confused with the Christian Churches & Churches of Christ). There are also those sociological cults that make headline news again and again: self-destructed groups as People’s Temple Christian Church (headed by Jim Jones), the Branch Davidians (headed by David Koresh), and Heaven’s Gate (headed by “Captain” Marshall Applewhite).

A doctrinal deviation (or tainted Christian movement) is better defined as a religious organization or movement that is generally Christian, but one that bears some cult-like characteristics (theologically or sociologically). Doctrinal deviations are probably not as deceitful or dangerous as cults, but neither are they are safe or sound! They are highly problematic at best.

Examples of doctrinal deviations include Roman Catholicism, Eastern Orthodox Churches, Seventh-Day Adventism, Serpent-Handling Churches, the “Word-of-Faith” Movement, “Holy Laughter” Revivals, the Faith Assembly, Crystal Cathedral Ministries, and the Metropolitan Community Church.

I agree with the words of the late Dr. Walter Martin: “The cults are the unpaid bills of the Church.” If the Church was more obedient to the Great Commission (Matt. 28:19; Rom. 1:16; 10:13-15), fewer people would be turning to cults for spiritual answers. Likewise, if the Church was more faithful to the written Word of God (2 Tim. 4:2-5), fewer people--both inside and outside the church--would be slipping into doctrinal deviations.