Sometimes it is difficult to know the difference between cults and the truth of what the Bible teaches because often times cults mix truth with error. They talk about believing in Jesus but they may worship a different Jesus than the one Christians worship.
All cults have one or more of the following beliefs: an impersonal God, lifeless idols, equality with God, no sin nature, universalism, no absolute truth, no distinction between good and evil, keeping some form of law, control over people, reincarnation, transcendental meditation, salvation by works, worshipping the creation more than the creator, women are inferior to men, a non-literal resurrection of Jesus, no such thing as illness, Jesus is not God in human flesh, altered states of consciousness, and no belief in the Trinity. This is NOT a comprehensive listing or detailed explanation. Read books on cults or false teaching for more information.
Cults or false teachings are almost always started by a human leader with a so-called vision or distorted teaching. Sometimes the distorted teaching is a single, isolated verse of Scripture taken out of context. Biblical truth is mixed with error, or other teachings are added to it. There can also be much deceit in the middle of it all. Human philosophies void of a credible source of belief further compound the problem.
Many times there is a "guru" involved, who can be defined as an "enlightened master" or even a "god-man," but not THE GOD-MAN Jesus.
Another term you will often hear or read about, especially in New Age thinking, is "karma." This is a belief that says good and bad actions result in an accumulation of "debt" during one's life.
Terms common to Christians mean different things to different sects. For example, the term "born again" to the mind science religions, means bringing forth the Christ already within you. Jesus is not the same as the one who Christians believe in. The Mormons' Jesus is entirely different than the Jesus of the New Testament.
If you are involved in any group, organization, or religious sect that teaches any of the above, or you know someone who is, it would be wise for you or them to get out immediately.
Here are two excellent books to read for detailed analysis of cults and false teachings: THE ISLAMIC ANTI-CHRIST, by Joel Richardson, and THE CHALLENGE OF THE CULTS AND NEW RELIGIONS, by Ron Rhoades
The Christian faith is based on the resurrection of Jesus, as told in I Corinthians 15:1-4, 14, and 17. "Now I make known to you, brethren, the gospel which I preached to you, which also you received, in which also you stand, by which also you are saved, if you hold fast the word which I preached to you, unless you believed in vain. For I delivered to you as of first importance what I also received, that Christ died for our sins according to the Scriptures, and that He was buried, and that He was raised on the third day according to the Scriptures...and if Christ has not been raised, then our preaching is vain, your faith also is vain...and if Christ has not been raised, your faith is worthless; you are still in your sins."
II Corinthians 13:5 says to "Test yourselves to see if you are in the faith; examine yourselves."
Here is the test of true doctrine as given in I John 4: 2. "By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God."