In Heaven, God's thought system entails profound sharing. Each part of the system contains the whole of the system. It is holographic. This is how God thinks.
"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 whole power of God's son lies in all of us, but not in any of us alone. God would not have us be alone because God does not will to be alone."
"Every altar to God is part of your Soul, because the Light He created is One with Him."
"One brother is all brothers. Every mind contains all minds, for everyone mind is one. Such is the truth."
"Every part is a container of the whole."
In that system, each child God created as a whole, producing multiple wholes, SHARES the whole of creation. That means, you have total access to *everything*, to experience it fully as if it were your own, while simultaneously EVERY other child is doing the same.
The key principle of Heaven, and Creation, is sharing. And so multiple children of God SHARE one mind, and that one mind is the "one son of God". Yet there are many children. Sharing is like "overlapping", literally co-existing in the same space. Your mind is plugged into the whole like how your computer is plugged into the internet and shares the internet with everyone else.
Before the separation idea there were ALREADY multiple individuals. There were already multiple children, who were so UN-SELFISH, that they were willing to SHARE everything with everyone. No-one wanted to be special or to have exclusive access to anything. Everyone was willing to ALLOW all of the others to share everything, themselves, and all that exists. It is the total absence of ownership. It is communal.
When the separation idea occurred, these pre-existing, eternally existing beings, decided to try to seek special favor from God. The idea was that they wanted to have something EXCLUSIVE, just for them, which the others did not have. They wanted to be SPECIAL. They wanted God to give them something which ONLY they had, and which others lacked. They wanted to be better than others. They wanted to be SELFISH. They wanted to find a way to shut out everyone else, to NOT SHARE ANYTHING, and to have something to call "just my own".
This produced a state in which souls, who were many prior to this, surrounded themselves with walls and barricades to try to "shut out" and EXCLUDE, "access", which all other souls had shared with them up to that point. Because even your own soul is something to be shared, you tried to not allow yourself to be shared WITH others. You put up a fence around your mind, to serve two functions: to keep them out, and to keep you in. This way you could fence off a tiny part of yourself and regard it as "exclusively mine", and stop everyone else from SHARING it directly.
In so doing, you withdrew from the collective shared experience of the sonship, you STOPPED SHARING, you went off into a corner and pouted by yourself, you attacked God and your brothers to try to keep them from sharing with you, and you created this illusion that you occupy a little space where NO OTHERS share with you, some kind of autonomous self-owned, self-run, isolated, personal PIECE of the whole, that you wanted to call your own SPECIAL self.
"Everything the ego perceives is a separate whole, without the relationships that imply sharing."
Doing this made you "alone". By trying to not share with anyone else, you stopped the RELATIONSHIPS that come with sharing, you closed the doors on your mind, you prevented access, and you said to the rest of the sonship "stay away, this is my castle and you can't come in." So then you find yourself pulling away from infinity, narrowing down, confining, withdrawing, isolating, imprisoning yourself, into a small tiny area of littleness, and that manifests as the condensing of thought into a BODY. A human body. Which is "a device for separation."
This body will then represent the idea that because you HAVE something exclusive that your BROTHERS do not have, you are now DIFFERENT to them. And this is also why every body is NOT THE SAME, on purpose. It's the idea of being UNLIKE anyone else, not equal, and unlike God. The body keeps all of creation OUT, and traps you IN, so that you can pretend there is some part of existence that is EXCLUSIVELY YOURS.
*THIS*.... is what it means, to have a separate self. It's got NOTHING to do with you being a self or not. It's got nothing to do with the fact that God created MANY SONS prior to the separation, which will CONTINUE after the atonement. It's got nothing to do with you being an individual. It's ONLY got to do with you attempting to NOT SHARE ANYTHING, within a realm where the total sharing of eveything is completely natural for all beings.
"The ego is the idea of selfishness. The soul is the idea of self-fullness."
So by trying to be SELFISH, in the midsts of a SHARED COMMUNITY, to stop communion, to stop communication, to take up arms against your brother, to PUSH OTHERS AWAY, and to try to EJECT them from your own shared experience, so that all that seems to be LEFT is you, THAT is the ego. That is what it means to be "separate". That is the separation IDEA. That's what the course means BY separation.
"Separation", as a word or term, does NOT MEAN, "there are many". It does NOT MEAN, "The presence of multiple brothers is an ego idea." It does NOT MEAN "there can only be one son." The fact there are many WHOLES who are HOLY, is NOT a problem whatsoever in reality. It is NATURAL. It's is God's Will. That you have a self, an individuality, is NATURAL. This has NOTHING to do with the tiny mad idea or separation from God. The separation is ONLY to do with you trying to STOP SHARING, in a realm where sharing is totally natural, prevalent, and something that everyone is doing.
It is not the creation of "a separate self", as if there was NO SELF before. You already HAD a self prior to the separation. The separation from God has NOTHING WHATSOEVER to do with the invention or creation of "a self", or multiple selves. The separation ONLY has to do with your *RELATIONSHIP* to others, your willingness NOT TO SHARE WITH THEM, and your attempt to EVICT THEM from sharing with you, so that all you end up with is YOUR SELF, in isolation, sharing with no-one. That's what the separation from God is all about.
The reversal of the separation from God will reconnect you to the sonship, restore your willingness to share everything with everyone that exists forever, join your mind back to other people's minds, make you willing to share your SELF with others and theirs with you, and to return to this state of Oneness, in which there is ONE MIND, but MULTIPLE BEINGS. Many souls, who are all alike and who share *everything* with each other without a single ounce of selfishness or possessiveness. THAT is heaven. That is natural. The end of separation and ego is NOT the annihilation of God's children, OR the end of your brothers.
So the separation from God merely means the rejection of a shared experience, and the attempt to bring an end to sharing, so that you can claim exclusive rights to some little piece of the whole that you don't want to share with others.
Having a separate self merely means your ACTUAL self is trying to pretend that it no longer SHARES anything with others, and so is "outside of" the shared communal experience AS IF it were "separate from it".
The ego, as the separate self, is nothing other than the rejection of the fact that you are PART OF everyone and are part of the WHOLE, as a SELFISH attempt to OWN part of the whole and call it your own, at the expense of others. It's your attempt to BLOCK ACCESS to your mind, from other minds, so that you SEEM not to be part of the whole anymore. When the ego ends, you simply stop being selfish and LEARN TO SHARE AGAIN. That's not the end of your SELF, ever. You in fact REGAIN more of yourself than you even have now, you expand your self, and you return to the WHOLE of yourself. "The soul is the idea of self-fullness."
So when we're talking about there being many sons in heaven, or many children, or "separate beings", we're NOT in any way talking about anything unnatural or against God's will. We're not even talking about the ego, or the separation idea, or the tiny mad idea. It's not until the MANY REAL BEINGS, the MANY PERMANENT BROTHERS, trying to compete with each other and vie for attention and be SPECIAL, that we start talking about the descent into ego, and the making of an illusory experience of "being separate". To be cut off in a body is to be ALONE, having disallowed anyone else to SHARE YOU. That's all it means to "be a separate self." A seeming outsider or stranger, cut off from the rest and having no relationships with anyone.
God's creation is perfectly natural containing multiple wholes, multiple individuals, multiple selves, multiple brothers, multiple beings, multiple minds. Because they all are willing to SHARE unconditionally and 100% with each other, coexisting in a communal state of total joining and freedom. It's only when someone starts trying to be special or selfish that we run into a problem. The end of the ego is the end of isolation, the end of exclusion, the end of selfishness, and a return to STILL EXISTING but SHARING EVERYTHING with everyone forever. The regaining of your natural inheritance, which is all of Heaven and all beings.
"We have also emphasized that man, insofar as the term relates to Soul, has not only been fully Created, but also has been created perfect. There is no emptiness in him."
"There can be no disinherited parts of the sonship, for God is whole, and all his extensions are like him."
"For in your part lies ALL of it, without which no part is complete, nor is the whole completed without your part."
"Though every aspect IS the whole, you cannot KNOW this, until you see that every aspect is the same, perceived in the same light, and therefore one."