Your belief in a thought from the not real ego wrong mind is what you are learning how to eliminate in a Course in Miracles (ACIM). Belief is intangible as it is activities like an agreement or investment of the mind in an particular idea or thought the christ. You use choice to invest belief in the ego thoughts which harvests the ability of the mind into the miscreation of this world. It is your belief in these ideas that is in need of forgiveness and what makes forgiveness appear difficult. Decision making in the mind is what you use all the time to think or not believe any thought at any given moment. This choice ability is where you have all the power to select from Heaven and terrible.
There are two famous lines in the Course about making the not real appear real and about ideas not leaving their source. Choice and belief are directly involved in both. Here's three (3) key descriptions of word symbols we'll consider to help expand the discussion:
Thought: An idea or opinion occurring in the mind.
Choice: The ability, act or possibility of making a selection between two or more ideas.
Belief: Accepting an idea as true or real.
If we look at these descriptions in order, it is readily apparent why the Course is aimed at your choice making (choice) ability in the mind which can observe thoughts (ideas) and decide to believe or not believe them. It is the remark ability where the choice is enabled to believe in the not real in order to revulsion belief in it (forgive) and thus correct the mind.
Making it Real
Students of the Course frequently do not understand what it means to make something real and how choice and belief are what does that in the mind. Having an not real ego thought, and choosing to think it, is what makes it appear real. It invests the mind and thus the idea stays with you as you've taken it seriously. Belief is judgment that you agree with the not real idea over reality.
Let's consider it another way. First, you simply go to the trouble of choosing to think in something, i. e., making the not real appear real, if it is "unreal" since the not real doesn't exist. If you chuckled and left it alone, what doesn't exist remains non-existent. Second, you will only go to very much trouble to prove that your not real idea is correct so because of this why the Course states that it precipitates to whether you want to be right or be happy.
Choosing belief in an not real idea is the choice to prove your idea correct thus making it appear real and forgiveness (withdrawing belief) appear difficult because you've invested a lot of effort into your miscreation and being right. That leads us to another location theme where ideas do not leave you as the source.
Ideas Don't Leave You
By itself, an ego thought is nothing (unreal) and will remain not real despite your choice to think the idea. It is the misperception of the results, or effects from assuming in the not real made real, that keeps the idea with you because you are still investing belief in the idea. You're adding further belief as you are still taking it seriously. The idea never left you because you never gave it up (forgave). The next logical step has to be to refute the truth.
In a mind split between the not real and real, the ego and God, what the Course is saying is that since the first not real idea of splitting up, and all the subsequent choices to mistakenly believe in not real thoughts as solutions, you've fragmented the mind. Forgiveness appears difficult because you are so committed to being right and so afraid of what you've done.
The Course is trying to tell you to start denying the not real lies of the ego and stop denying the truth. Do the other of what what you are doing now. Look at your location choosing to invest your beliefs in the mind so you can learn how to eliminate (correct your mind) which is to withdraw belief in the not real. The fear of God is also an not real idea you think in. You've actually "done" nothing as the not real doesn't exist.
To think Means Denial, Repression and Projection
These are key ego safeguarding because of the guiltiness behind the option to think the not real. Without doing Course details, all of us are aware of guiltiness and have chosen to continue with the ego's not real ideas about what to do with the guiltiness. No one on earth is exempt. You can pretend otherwise, but that's denial and repression and assuming the ego. They lead right to projection.
Let's look at the word symbol descriptions:
Refute: Refusal to admit the truth.
Denial: A statement or affirmation of something as not true.
Repression: Suppression a thought or feeling.
Projection: A mental image known as reality.
You cannot refute and repress if you do not first went to the difficulty of making the not real real and keeping the idea with you. The guiltiness behind those choices disturbs you. Not only have you repudiated to admit the truth, but you've also refused what you've chosen. That's double the guiltiness annoying you and if repressing doesn't work, you'll project it "out there" into a world and bodies mistakenly perceived as "reality. inch
Projection doesn't hide guiltiness. It leads to responsibility and attack to help expand the belief in guiltiness which is also an (earlier) not real idea where the mind thought i would invest belief. Again, belief is judgment. The ego only survives by judgment. Forgiveness is pulling out belief in what is not real.
To not Believe Is to Eliminate
Consider the immense power this decision making ability has in the mind if you will only stop and return in your head and observe what you are going for to think or not believe. You have forgotten that choice for wrongly recognized belief in the not real, what doesn't exist, is all that is going on. What exists is real. The peace of God is in forgiving or pulling out belief in the not real and returning your brain to the real.
It is only from noticing you will learn what the cost of continued choice for belief in the not real world of projections really exacts as well as continuing to repress and refute the guiltiness. Likewise, it is only from noticing that you can learn to recognize those beliefs and how to give them up (forgive). You must face what being right is really costing you. This is a world of ever-changing unhappiness, pain and suffering, filled with responsibility and attack, and where momentary happiness is deemed better than endless happiness.
When that cost isn't worth it, you will take the time to learn how to give up your beliefs in your wrongly recognized choices of where to invest the mind. Heaven waits merely on this recognition and readiness to unlearn what you have taught yourself and grow taught by a different internal Teacher how to choose again (forgive, correct your mind). Endless happiness is from choosing what is constant and real (Truth). It is unchanging and therefore, wholly dependable because it is whole.
To choose once again the truth is to search and observe in your head for these beliefs in the not real and then choose to give them up (forgive). Just as the world is not real, neither are beliefs. Choice for investment tends to make belief appearing real in the mind.
The light of "the splitting up never happened" (the Atonement) stands out for you choice by choice, gradually lighting the way home as you withdraw belief (forgive). Forgiveness is the main solution, the Atonement Principle that's an act of Love by the Father in answer to His Beloved Son having a silly not real idea of splitting up, choosing to think it, and further choosing keep it with him.
Beyond this world is the beauty in our True Self where Love is extended throughout everlasting in a Song of Prayer between the Father and Son, Creator and Created as you. If the ego's foundation is splitting up, then salvation's foundation is sameness. This world as evidence of the idea of splitting up still being with us means that we must all observe and eliminate our mind back to sameness within our not real ideas which have not left their one source. All us is a fragment of the One and the decision making mind is where we all have the choice to think or not believe.