Excellent topic DCMS! Here are some quotes from some different sources that you all might find interesting:
Definition of a cult
THE ORIGINAL USE OF THE WORD "CULT" AS WELL AS IT'S USE TODAY DERIVES FROM THE LATIN WORD "CULTUS" WHICH MEANS "WORSHIP".
DICTIONARY DEFINITION- A GROUP BOUND TOGETHER IN A INTENSE DEVOTION TO A PERSON, IDEAL OR THING; A SYSTEM OF BELIEFS AND RITUALS THAT ARE BOGUS. In other words they are practicing a false system of spirituality while claiming to be authentic.
In 1912 Ernst Troeltsch in the book social teaching of the Christian church, classified religious groups in three groups: "Church", "sect", and "cult". A cult represented a mystical or spiritual religion to intellectuals and educated classes.
With a more Biblical perspective, in 1938 Jan Van Baalens' "The Chaos of Cults" critiqued Theosophy, Mormonism, Christian Science, and Jehovah's Witnesses as 'Cults.' Because they were aberrant in their teachings while claiming to be Christian.
Christian apologist Robert Bowman defines a cult as A religious group originating as a heretical sect and maintaining fervent commitment to heresy. Adj.: "cultic" (may be used with reference to tendencies as well as full cult status.( Robert Bowman, A Biblical guide to Orthodoxy and heresy.)
Cult's will say they are the way to Christ and Christ Himself is not the way. So they put themselves as a group or their teaching in between man and God. They become mediators between God and man. They do not have the Christian distinctive, but will claim to be Christian in their beliefs and practices. It was Christ himself who Said "I Am the way, the truth the life."
A THEOLOGICAL DEFINITION A THEOLOGICAL DEFINITION OF "CULT" MUST BE BASED ON A STANDARD OF CHRISTIAN ORTHODOXY. USING THE BIBLE'S TEACHING AS A FOCAL POINT. A CULT IS ANY RELIGIOUS GROUP THAT CLAIMS TO BE CHRISTIAN (OR MAY NOT BE) IS DISTINCT AND HAS DOCTRINES AND PRACTICES THAT CONTRADICT THOSE OF THE SCRIPTURES AS INTERPRETED BY ORTHODOX CHRISTIANITY. THOSE THINGS THAT HAVE BEEN UPHELD IN HISTORIC CHRISTIANITY .
ORTHODOXY IS REPRESENTED FROM THE BEGINNING OF THE CHURCH, AND IS EXPRESSED IN STATEMENTS SUCH AS THE APOSTLES CREED WHICH ARE DENIED . THEY WILL DENY THE BIBLE AS THE COMPLETE BOOK OF REVELATION AND OUR GUIDE TO KNOWING GOD. THEY WILL DISTORT THE CENTRAL MESSAGE OF THE SCRIPTURES AS CHRIST BEING THE SAVIOR ALONE. THEY WILL DENY HIS DEITY AND DISTORT HIS NATURE. THEY FORM THEIR GROUP AROUND A SINGLE PERSONS INTERPRETATION OF SCRIPTURE, OR CHRIST USUALLY BY A NEW REVELATION. THEY REMOVE THEMSELVES FROM THE LARGER BODY AND OPERATE AUTONOMOUSLY. A CULT IS ORGANIZED HERESY. THEY WILL DISTORT ONE OR MORE OF THE FUNDAMENTALS.
Walter Martin described a cult like this: "as a group of people gathered about a specific persons interpretation of the bible... from a theological view point, the cults contain not only a few major deviations from historic Christianity. They paradoxically, they continue to insist that they are entitled to be classified as Christians." (Kingdom of the cults p.11)
In his book The New Cults, Walter Martin defines a cult as “a group religious in nature which surrounds a leader, or a group which either denies or misinterprets essential biblical doctrines.”