I am indebted to my good friend, Wheaton College Professor Emeritus Dr. Morris Inch for bringing this manipulative technique to my attention. Even though it is one of the more obvious features of both cults and spiritual abuse, this one is often difficult for people to describe. "Esoteric" can mean either "intended for or understood by only a chosen few, as an inner group of disciples or initiates (said of ideas, doctrines, literature, etc.)" or "beyond the understanding or knowledge of most people" (Webster's New World Dictionary, Third College Edition, 1988, p. 464). The latter definition is virtually synonymous with the meaning of "mystical," and many spiritually abusive groups are mystical, but it is the former definition that applies most frequently.
Spiritually abusive groups have their own doctrines and their own in-house jargon which they claim can only be truly understood by those who "truly belong." Such people are the only ones who are "true Christians."
These groups love to quote the Apostle Paul's words:
But a natural man does not accept the things of the Spirit of God, for they are foolishness to him; and he cannot understand them, because they are spiritually appraised.
[1 Corinthians 2:14, NASB]
So if you don't understand what the group teaches, you must be "a natural man" (literally, "an unspiritual man," NASB margin; or a "man without the Spirit," NIV). It must be because you do not have God's Holy Spirit. Therefore, you must not be a Christian.
The only problem with using that verse this way is that it is not what Paul meant. Anyone who reads the whole chapter through from the beginning will quickly realize that "the things of the Spirit of God" do not refer to just any teaching, much less the peculiar teachings of a spiritually abusive group. In the context of 1 Corinthians 2, "the things of the Spirit of God" refers specifically to the Gospel of Jesus Christ -- the Good News of His death on the cross for our sins.
The reason that "the things of the Spirit of God" concerning the cross of Christ are "foolishness" to the "natural man" is because he rejects them, and refuses to appraise them from God's point of view -- not because they are intellectually unintelligible to everyone except believers.
This is what Paul is actually saying in the context. But spiritually abusive groups will never encourage you to read the surrounding context of the verses they quote, because if you did, you would figure out that they are twisting the Scriptures.
In my group, the leader would cloak his meaning in buzz-words from pop-psychology.
Other groups usually confuse new members with spiritual-sounding clichés. And no matter how long you are a member, you never seem to really master the in-house jargon. This is often because the leadership is careful never to give fully-understandable definitions of the terms it uses. This way it can always keep you off-balance, so that if you ever step out of line, it can always quote verses like 1 Corinthians 2:14 in order to frighten you back into submission.
Sometimes leaders will also appeal to the fact that Jesus spoke in parables. But they don't mention that Jesus also explained His parables to His disciples. He clarified their meaning. Why don't spiritual abusers do the same? Because while Jesus was concerned with teaching people, spiritual abusers are concerned with controlling people, and one method of controlling is to keep them confused.
But it goes beyond the mere use of jargon. These groups have an esoteric approach to "truth" in general. Unlike the authors of the Bible, who go out of their way to make things clear to their readers, spiritual abusers make things unclear and confusing. In these groups, true understanding always seems just slightly out of your reach. Others in the group pretend to understand, and perhaps you pretend as well. But eventually you figure out that they are just as perplexed as you are, even though they will never say so as long as they wish to remain members.