From Chapter 3 of The Nature of Personal Reality by Jane Roberts:
“Ideas have an electromagnetic reality; Beliefs are strong ideas about the nature of reality. Ideas generate emotion. Like attracts like, so similar ideas group about each other and you accept those that fit in with your particular “system” of ideas… You get what you concentrate upon. There is no other main rule.
It may be easy for you to see beliefs that are invisible to others in themselves. Reading this, you may be able to point at friends or acquaintances and see clearly that their ideas are invisible beliefs which limit their experience – and yet be blind to your own invisible beliefs, which you take so readily as truth or characteristics of reality.
Your sense data, again, will most definitely reinforce your ideas. You will also react clairvoyantly and telepathically to inner information at an unconscious level that is, once more, “collected” under the organization of your quite conscious concepts concerning existence in general, and your own in particular. So you are locked into physical situations that are corroborated by the great evidence of sense data – and of course it is convincing because it reflects so beautifully, so creatively, and so actively, your own ideas and beliefs, whether they are positive or negative…
It is the core belief which is strong enough to so focus your perception that you perceive from the physical world only those events that correlate with it. It is also the strength of the core belief that draws up from the vast bank of inner knowledge only those events that seem to fit within its organization.
Now let me give you a brief example of a core belief. It is a blanket belief: human nature is inherently evil. This is a core belief. About it will spring events that only serve to reinforce it. Experiences – both personal and global – will come into the perception of a person who holds this belief, that will only serve to deepen it further.
From all the available physical data of newspapers, television, letters and private communication, he or she will concentrate only upon those issues that “prove” that point. Suspicion of others will grow, to say nothing about the individual’s personal distrust. The belief will reach into the most intimate areas of his or her life, and finally no evidence will seem to be available to disprove it.
This is a sample of an invisible core belief at its worst. A person holding it will not trust a mate, family, friends, colleagues, country, or the world in general. You make your own reality. I cannot say this too often. There will be periods where all of your beliefs are at an even par, so to speak. They will agree. The ideas may be quite limited. They may be false. They may be based upon premises that are not true. Their vitality and strength however will be quite real, and seem to bring excellent results…
The truth is then that you form your reality directly. You react consciously and unconsciously to your beliefs. You collect from the physical universe, and the interior one, data that seems to correlate with your beliefs. Believe, then, that you are a being unlimited by nature, born into flesh to materialize as best you can the great joy and spontaneity of your nature.
Core beliefs are those about which you build your life. You are consciously aware of these, though often you do not focus your attention upon them. They become invisible, therefore, unless you become aware of the contents of your conscious mind. To become acquainted with your own ideas and beliefs you must walk among them, symbolically speaking, without blinders. You must look through the structures that you have yourself created, the organized ideas upon which you have grouped your experience…
The core belief, because of its intensity and because of your habits, will often tend to attract to itself others of a like nature. They will hang on. If you are not accustomed to examining your own mind, then you can allow separate growths of this kind to form about a belief until you cannot distinguish one from the other. This can develop to such an extent that all of your experience is seen only in relationship to this idea- growth. Data that seems unrelated to this core belief is then not assimilated but thrown into the corners of your mind, unused, and you are denied the value of the information.
A core belief is invisible only when you think of it as a fact of life, and not as a belief about life; only when you identify with it so completely that you automatically focus your perceptions along that specific line.
The structuring of beliefs is done in a highly characteristic yet individual manner, so you will find patterns that exist between various groupings, and one can lead you to another.”
More about the role of beliefs in creating your reality in the Understanding Reality Course