If you as Christ, God's Son, are "one with God", does that mean you do not exist as an individual being/son? Does it mean there is only God and NO son? No. It also does not mean that your "brother" is an "ego idea of separation". Brothers are co-children of the same Father - God.
In not one single one of these statements does "one" mean a count of one.
"This appears to contradict another statement: "I and my Father are one." It doesn't. ***There are still separate parts in the statement, in recognition of the fact that the Father is GREATER***. Actually, the original statement was "are of one KIND."
"This is because ***God and man are NOT equal***"
"The creative power of both God AND His Creations is limitless, but it ***is NOT in reciprocal relationship.*** You DO communicate fully WITH God, as He does with YOU. This is an ongoing process in which you SHARE, and BECAUSE you share it, you are inspired to create LIKE God. But in Creation ***you are NOT in a reciprocal relation TO God***, because He created YOU, but you did NOT create Him. We have already stated that only in this respect your creative power differs from His."
"I and my Father are one with you, for you are part of Us."
"Your Son is one with You in being and in will, and nothing contradicts the holy truth that I remain as You created me."
"Nothing has power over you except His Will and yours, which but extends His Will. 8 It was for this you were created, and your brother with you and at one with you." (oneness is happening at the same time as you AND your brother existing as creations of God!!!)
"You and your brother are the same as God Himself is One, and not divided in His Will. 2 And you must have one purpose, since He gave the same to both of you. 3 His Will is brought together as you join in will, that you be made complete by offering completion to your brother."
"I trust my brothers, who are one with me." (not "who are egos with me"!)
"His Oneness and ours are not separate, because His Oneness encompasses ours." (two onenesses? WTF, OMG, call the the course police)
"Your role in the redemption LEADS you to it, by re-establishing its oneness in your minds."
"And ONLY as you look upon him as guiltless, can you understand his Oneness."
"Nor do they love the Oneness which created them as One with Him."
"In unity with Him do they abide, and in their Oneness both are kept complete."
"Its truth established you as one with God."
"we stand together as one Son of God."
"every heart throughout the universe forever sings as one"
"As a man and as one of God's creations, my right thinking, which came from the Universal Inspiration which IS the Holy Spirit, taught me first and foremost..."
"In this equality is Christ restored as one Identity, in Which all Sons of God acknowledge that they all are one."
"He loves you both, equally and as one."
"When two minds join as one, and share one idea equally, the first link in the awareness of the Sonship as one has been made."
In none of these statements do the "two" cease to exist as two. This does not mean separation persists either. Nor does it mean that "two" always indicates "multiplicity of egos". Nor does multiplicities of brothers created by God in reality mean there is separation happening.
Separation does not mean "counting how many", any more than oneness means "a count of one". Separation ONLY means the attempt to be exclusive, selfish and isolated, in among a large group of individuals with whom you were previously sharing everything.
So many myths to dispel.