As I have said on several occasions now, Earburner, you are a very... interesting... person, with interesting... thoughts. :) I don't completely disagree with you, but there are a few... quite significant :) ... differences. Neither the Father nor the Son are the Holy Spirit ~ or "holy spirit," as if it is only some George Lucas kind of "force") ~ but the Father and the Son are both one with Holy Spirit, and He with They. Understanding differently from that is not Biblical. Jesus, in both John 14 and John 15, clearly refers to the Holy Spirit in the third person, not the first, and very much separate from the Father and Himself.Comprehend Hebrew 10:19-21 by understanding that we can now approach God, but only through Jesus, of Whom God indwells.
Therefore, the Father dwells in us indirectly, through the Veil of Jesus Himself, and in no other way.
If the Spirit of Jesus is not within us, we are assured neither is the Spirit of the Father!! Together, they are Holy Spirit. You can't have one without the other:)
Heb. 10
[19] Having therefore, brethren, boldness to enter into the holiest by the blood of Jesus,
[20] By a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh [Immortal flesh];
[21] And having [now] an high priest over the house of God;
As it pertains to the symbolism of the temple veil being torn in two, it is speaking about the new and living way to enter into God the Father's Presence, of whom dwells WITHIN the Spiritual, Immortal Flesh of Jesus, the only Mediator between man and God the Father.
A third "add on" to the Godhead of Two, is not a separate, additional Spirit of God the Father and/or the Son, but rather it is a goal of function by the Two, being One IN SPIRIT.
Their Oneness in Spirit is 100% visible in Romans 8:8-11, which again is saying: you can't have One without the Other.

Grace and peace to you.
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