As Jesus says, "the separation has occurred". The separation is another name for the fall of man. We did in fact "fall asleep" and dream of another world in which we believed in and thus made/maintained "en ego". It has not been fully created because it is not created, but made. But we DID have the tiny mad idea and enter into dreaming.
"The Separation HAS occurred. To deny this is merely to misuse denial. However, to concentrate on error is merely a further misuse of legitimate psychic mechanisms. The true corrective procedure, which has already been described as the proper use of the spiritual eye (or true vision), is to accept the error temporarily, BUT ONLY as an indication that IMMEDIATE correction is mandatory. This establishes a state of mind in which the Atonement can be accepted without delay."
In heaven, God thinks holographically. The whole, which God is, creates. Anything he creates must be like himself. Therefore his sons/creations must also be completely whole. To be whole, and given God is everything, they must share all of God. So now you have parts, which are wholes in and of themselves, which also share with and are joined with the whole in "oneness". All the creations are of like kind, whole like God. And also the sons of God who are wholes also create whole children.
"You had everything when you were created, just as everyone did."
"The recognition of the part as whole, and of the whole in every part, is perfectly natural. For it is the way GOD thinks, and what is natural to Him, IS natural to you."
"The soul is the idea of self fullness."
"The soul has not only been created perfect it has been fully created. There is no emptiness (unwholeness) in it."
So we have this whole, which creates more wholes, which are whole as individual beings and who also share the whole with all other wholes.
"God who encompasses all being (is the whole) nevertheless created separate (distinct parts within the whole) beings who have everything (the whole) individually (as whole sons/beings) and want to share it (sharing is fundamental to reality, true sharing is oneness) to increase their joy."
The part where the separation comes in is, where a part, which is a whole joined to the whole, attempts to disconnect itself from sharing the whole. It tries to cut itself off from the whole of God and from its brothers that were previously sharing everything with it.
"Everything the ego perceives is a separate whole, without the relationships that imply BEING."
So a son of God puts a fence around what appears to be himself, the "part as a whole" individual self, and tries to isolate it from the sharing/communicating-with portion of itself. It tries to "become separated" from sharing with anyone or anything. This turns it into a "part which is not sharing". Which is the idea of selfishness.
"The ego is the idea of selfishness."
Having become "separated off" ie isolated from sharing with the family, we are now "the separated ones" and we have a "separated self". But this doesn't mean we invented a self at this point, it just means we took our self and imprisoned it in a body concept.
"The body is clearly a device for separation."
"The body is a fence the Son of God imagines he has built to separate parts of his Self from other parts. It is within this fence he thinks he lives, to die as it decays and crumbles. For within this fence he thinks that he is safe from love (shared wholeness)."
By imposing upon ourselves ideas of "not sharing with the whole", we necessarily shut out some portion of our self which was shared with the whole. And that now means that we are seeing and experiencing ourselves as "partly myself", or a part which has no wholeness. This "partial self" is hemmed in by illusions of separation, and it confuses itself with these illusions and believes they are true of it, thus defining it. This produces "the ego" in the mind, which is basically a belief by a fundamentally whole/joined entity that it is not whole/joined. It's self denial. The ego is the idea of what you are not, which is an attempt to destroy your whole self, which leads to death.
"The body is the means by which God's Son returns to sanity. Though it was made to fence him into hell without escape, yet has the goal of Heaven been exchanged for the pursuit of hell. The Son of God extends his hand to reach his brother, and to help him walk along the road with him. Now is the body holy. Now it serves to heal the mind that it was made to kill."
To awaken we have to undo the illusions of imprisonment by not believing in them, opening and expanding our sense of identity to align our mind with our soul, reconnect with God and the sonship through total sharing (holy relationship), and thereby disappear the egoic selfish idea of being "separated off". Thus we regain and re-inherit our inheritance from God, reclaim our identity as part of Christ, and resume our position in the sonship. Wholeness is restored and we return to being whole (aware of it) and to being "one with God", ie sharing everything with God and the whole Kingdom.