Would the dimension of spirit be everywhere and perhaps parallel to our observable universe?
It would seem the Holy Spirit can go in and replace our human spirit…or at least part of our human spirit. Some people may have more of the Holy Spirit in them depending on their state of grace.
Would the Holy Spirit replace our human spirit? Hmm. Good question. It says (Galatians 2:20) that “I have been crucified with Christ; and it is no longer I who live, but Christ lives in me.” And that would seem to indicate that the human spirit is actually replaced, in some sense, by the Spirit of God. Also, John the Baptist says in reference to Christ (John 3:30) that "He must increase that I might decrease. You could maybe also say that we are to give up our spirit when we are in a sense crucified throughout our lives (when we meet trials and so forth), just as Christ gave up his Spirit on the Cross. On the other hand, maybe our human spirit isn’t actually replaced but merely resurrected in harmony with the Holy Spirit. I have no idea. We need to a theologian on this.
I assume, when you ask about “dimensions” of a spirit, you are talking about spacial, quantifiable measurements of the spirit. My inclination is to probably say no … but, on the other hand, you could say that is particular spirit is “here and not there” depending on where’s it
acting or simply doing something in the physical universe. Aquinas says the soul is the act of the body, and so you could say that your spirit is, to say the least, where your body happens to be at the time. Also, for purely immaterial spirits (angels and demons), when they act in a physical location in the universe, they are said to actually be there as well (Aquinas says this). So, therefore we could assign some kind of quasi-dimensionality to them.
But then there is the interesting question of bilocation and other such topics. First of all, you mentioned something about astral projection. It seems to be the case (this is my private philosphical and theological speculation) that astral projection and what we call bilocation are very similar, except that bilocation (the thing we see with certain saints) is sanctioned and guided by the Holy Spirit. Astral Projection seems to be possible and manifests itself much like bilocation sometimes (it sends your consciousness far away from you body, and can even produce a life-like representation of your body … an “ethereal” body perhaps … who knows). When someone practices astral projection they become more conscious and can perceive more clearly the spiritual realities around us and can run into other “travellers” along the way, either other Astral Projectors or Angels or Demons. The reason why Astral Projection is condemned by the Church is that you throw yourself into, as it were, a “spiritual ghetto” where demonic spirits can take advantage of you, as you have put yourself into a very vulnerable, sensitive spiritual state. It can mess you up. Bilocation seems to be the term we use for saints (or very spiritual and holy people) moved by the Holy Spirit to do this exact same thing, except, it’s the Holy Spirit that’s guiding and protecting them from malignant forces. Padre Pio, when asked if he could explain what was happening when he bilocated, said something like, “My being was extended.” (I might be wrong. I heard this somewhere.) If something can be extended, it can therefore, in theory, be measured spacially. So, if his spirit
was acting in that faraway location, and we say that a spirit is “there” when it’s acting “there,” then we could possibly attribute dimensionality to a spirit in a vague and perhaps somewhat unmeasurable way (I guess). I might be wrong about all this. Any thoughts?