1) Did I claim to know what goes on in heaven? Nope - thus obfuscationHow do you know what goes on in heaven? Have you been there? Here is more of the quote from 1 John 5.
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1 Jn 5:4 For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith.
5 Who is he that overcometh the world, but he that believeth that Jesus is the Son of God?
6 This is he that came by water and blood, even Jesus Christ; not by water only, but by water and blood. And it is the Spirit that beareth witness, because the Spirit is truth.
7 For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.
8 And there are three that bear witness in earth, the Spirit, and the water, and the blood: and these three agree in one.
9 If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.
10 He that believeth on the Son of God hath the witness in himself: he that believeth not God hath made him a liar; because he believeth not the record that God gave of his Son.
20 And we know that the Son of God is come, and hath given us an understanding (about being born again as the children of God), that we may know him that is true, and we are in him that is true, even in his Son Jesus Christ. This is the true God, and eternal life.
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The point of this whole section is to show the oneness of God in the physical and the spiritual and how the possession of Christ in the person of the Holy Spirit in the body of the believer unites that believer with the trinitarian God, thus making the believer a trinity as well with all the godhead involved. This is possible because Christ is spirit as well as physical and he is from heaven and from earth and your omission of certain words obscures things we need to learn from this passage. He is the person who makes God and man one through a new birth that could not be achieved without him.
I think your omissions in your favorite books are more than a little bit wrong. I do not think you can get understanding that are in these words from your books.
2) Nothing wrong with interpreting and commenting on scripture. The issue is rewriting scripture and claiming the corruption is scripture.