Trinitarianism

I'm using my developing philosophy and deepening faith which is moving beyond Christianity and bringing in the Holy Spirit and our Heavenly Father more as Creator. It is a slight merging of New Age and Christianity with elements of the Ancient Celts.
This is very much a part of my personal faith though I have not defined it in any great detail. Basically keeping an open mind and placing myself within the protection of the Holy Trinity.

Having just done so for this post, I want to add my story is sci-fi and I am bringing in the Creator/Spirit beliefs of my Sentient Dragons.
If anyone would like to share ideas worth expkloring by mainly Trinitarian humans and Senient dragons, or just would like to discuss Triniarianism pleas do so.

Consider reviewing the literature on Arian Christianity and the intrigues surrounding the codification of the Nicene Creed in the 4th Century (that would be A.D.).

You might conclude, upon reading this material, that trinitarianism is somewhat arbitrary in the grand scheme of things, and was extorted at the point of a Roman sword.

It isn't. My own revelations have shown it to me.

If your dragons are primarily individual rather than social beings - they don't so much have society or community as they have "here's what you may not do to another dragon, or all the other dragons will punish you for it", say - then they might not understand a human trying to describe the Trinity as fundamentally a community of Persons. ("Why would God the Father even want to perfectly express His own Self? Nobody else needs to know anything about me!" or "If God the Father and God the Son are distinct Persons, why wouldn't they stay as far away from each other as possible and have as little to do with each other as possible?")

If, on the other hand, they're much less individual than we are, they might not understand why that's significant to us. ("Why is God special for being able to perfectly express His own Self? I can do that by telepathically showing someone whatever is most important about me!" or "Why are God the Father and God the Son special for loving each other with a totally self-giving love? How could anyone love someone else without being utterly self-giving?")

As you are relying on personal revelation, what is it about the Trinity that you would like to discuss?

Your movement beyond Christianity, while placing the Father in the creator role, and keeping the Holy Spirit, reads as Arian or even Judaic to me. It seems to discard the trinity in the sense of three co-equal elements that are all aspects of a single deity.

Not quite. The three equal persons in One God seems to have been almost forgotten by Christianity which does not seem to place equal emphasis on the 3 persons in the Triune deity. The Creator seems to me to deserve more emphasis than He gets.
I've been wondering what the growth of New Age stuff meant and then saw the lack of emphasis on the Creator in Christianity as a whole Is that what the Holy Spirit wants us to see? Judaeism missed that acceptance of Christ, have Christians missed out a bit of the Holy Spirit???...

That depends on whether or not you consider "the Creator" to be one of the Persons in the Trinity. Catholicism, for example, considers "being the Creator" to be a property shared in some sense by all three. (For this reason, we don't consider baptisms "in the name of the Creator, the Redeemer, and the Sanctifier" to be valid; to us, those are not the Persons of the Trinity.) For us, neglecting that part of God's nature is equivalent to neglecting, say, God-as-Heavenly-King or God-as-Lord-of-Hosts; not good, but not the same as ignoring one of the Persons of the Trinity.

(For that matter, I can readily find examples from the vast treasury of Catholic prayers where worship is directed to the Father-as-Creator, the Son-as-Creator, or the Holy-Spirit-as-Creator. The first and last would be easy; the second might take some work, but I know I've seen some. Would you be interested in seeing that, if I did?)

The Catholic understanding of trinitarianism is based on an Aristotleian-Thomistic view of the universe (as in, it's derived from the philosophies of Aristotle and Thomas Aquinas).

We believe that there are three seperate divine persons in one being. How is this possible?

Well, first, let's consider an example of a "being" that is not a "person": a dog. It's clearly a being, and yet is not a person. This does not prove that the concept outlined above is logically possible, but it does make it clear that "person" and "being" are not synonymous.

The Son is eternally begotten of the Father and the Holy Spirt proceeds from the Father and through the Son (side note: The phrase "and the Son" is known in latin as the filioque, and its addition to the Nicene Creed was one of the reasons the Orthodox Church split from the Catholic Church. Nowadays Catholics consider the Creed with or without the filioque valid as long as the understanding of the Trinity is the same in both versions of the Creed, but the Orthodox seem generally more unwilling to give ground on this one for various complex theological issues that are hotly debated).

The Father, the Son, and the Holy Spirit always existed; there was never a time when there was "only" one of the three. Catholics believe that the role of the Father in the Old Testamentwas to "raise" the children of Israel as a father raises its children; hence, our understanding of God the Father has evolved over time (although God has never changed). This is also the reason that only the Father seems to be mentioned in the Old Testament; "raising" the children of Israel is the role most properly delegated to the Father, and that is what the majority of the Old Testament is about.

Of course, the other two persons in the Trinity are also there. Catholics believe that the Holy Spirit speaks through the Old Testament prophets and that the Messiah (the second person of the Trinity, the Son) was prophecied there. He is also the actual personification of Wisdom itself, as seen in the (deuterocanonical, or according to Protestants apocryphal) Book of Wisdom (this, however, is a debated point. I think it makes sense, though).

When we say that the Son was eternally begotten of the Father that is important; there was never a time when the Son was not present with the Father, since God is eternal; likewise, there was never a time when the Holy Spirit was not proceeding from the Father through the Son.

All three are eternal, unchanging persons. They are, however, one being, as in, they have the same substance (they are all fully God); they are all omnipotent, omniscient, and omnibenevolent. A proper understanding of the philosophy believed by the Catholic Church tells us that it is logically impossible for there to be more than one of these beings; therefore, we must believe that they are three persons in one and only one being.

When we say that the Holy Spirit proceeds from the Father through the Son, we mean that the Spirit is among us and always was; he is the messenger of God who gives us supernatural gifts.

We also believe that it is impossible to logically prove the Trinity's existence. We can only prove that its existence is not contradictory. We believe in the Trinity's existence because we have rational reasons for believing Catholicism is the correct religion, and it teaches us that Trinitarianism is correct; in other words, we believe it on faith. As St. Augustine once said (paraphrased), trying to understand the Trinity is like trying to pour the ocean into a bucket; it's much too grand for human minds to comprehend.

I hope this helps!