Hi Leolaia, interesting.
Of course, the Father, Son and Holy Spirit were not the only "triadic formulae" in scripture.
Of note the Ark and two "covering cherbus" were another three. The Ark of the Covenant represented some reference to the Father and his sacred holiness. The two angels which were on the top of the Ark of the Covenant and whose wings touched and were held over the ark were called the "covering cherubs". Satan was one of these two angels, Michael the other. When Satan rebelled then Michael kicked Satan off symbolic Mount Zion....
"And i shall put you as profane out of the mountain of God, and I shall destroy you, O cherub thatis covering, from the midst of the fiery stones."
To fast forward on this, because Satan and Michael were in this special position with respect to god, they formed a trinity, a unity of three. The two angels, Michael and Satan, were depicted on the walls of the temple and on the curtains, alternating the image of a cherub with a man's face (always a reference to Michael/Jesus the "son of man") with a palm tree. Thus even the Satanic-inspired imagery of being a beautiful goddess in the form of a tree is based upon the heavenly representation of a tree, and a palm tree at that. This relates to the tree of knowledge and that relates to feeding from this tree and giving knowledge and thus Isis is presented as a tree goddess with a breast giving suck to her followers. Knowledge is thus a critical thing for Satan, only for Satan it becomes disinformation and propaganda disguised as "education".
The milk-giving goddess was typified in another popular form in the goddess Artemis of Ephesus who had many breasts like dates (you can see photos of this goddess on the internet), but with legs bound close together she resembled a "palm tree" which goes back to the theme of Satan being a femine representation, generally, particularly in relation to Michael who becomes her husband. Thus the pagan-inspired "Song of Solomon" (not inspired book) which makes many references to the many forms of the Mother Goddess at 7:7 "This stature of yours does resemble a palm tree, and your breasts date clusters."
These are some links to various forms of the goddess described in Song of Solomon....
http://www.uwgb.edu/sophia/illustrations/images/artimus.htm
http://www.thewhitemoon.com/gallery/Artemis2.html
http://www.uwm.edu/Course/mythology/0600/751d.jpg - black Artemis.."A black girl I am"
http://www.uwm.edu/Course/mythology/0600/751e.jpg -- 4:1 "Your hair is like a drove of goats that have hopped down from the the mountain.."
Thus getting back to the trinity, it was likely to both Satan and Jesus that God was speaking in Eden when he said: "Let us make man in our image....male and female", the reference to the female and thus the "woman" being to Satan. Thus Satan is referred to as the "woman" in Genesis 3:15 when god was speaking to Jesus when he said: "I will put enmity between you (Jesus) and the woman (Satan) and between your seed and her seed." -- setting up the centuries long competition between Satan and Jesus, clamaxed in Revelation when Jesus finally kicks Satan out of Heaven. BUT... that brings us to another Christian trinity concept, that of the Father, the Son and the Church.
The Chuch, becoming the Bride of Christ, a select "144,000" (probably 1,440,000, 144K x 10) also takes the place in the trinity and thus becomes "God's temple" where he dwells. So the new Christian trinity is the Father, the son and the Church when you take reference to the original trinit of the Father (represented by the Ark of the Covenant) and the two covering cherubs.
This concept thus makes it a little awkward for the formal trinity doctrine to be that of the Father, the Son and the Holy Spirit. But no more awkward than say "in practice," with Catholics, the clear trinity is the Father, the glorified Mary and the Son.
I certainly see a sort of academic push to connect somehow, the woman with wisdom and the wisdown with holy spirit and then holy spirit with the Shekinah and back to the woman again, but it's awkward. There is not a clear concept of the woman/Mary being exchangeable for Holy spirit. Even the dove associated with Athena lends itself to Holy Spirit, but who Mary is in the Trinity and the Mother Goddess in the pagan trinity of the Husband/Son/Mother is a clear cross-over with much written about that, but Mary and Holy Spirit are not linkable in the Christian context of who the Goddess Mary is compared to Holy Spirit.
So anyway, the "trinities" are definitely there and in the foreground, whether defined as three equal gods or not is another issue.
By the way, I definitely believe that the "666" Beast is a reference to the Trinity, only as a false, non-orthodox Christian doctrine. The 666 identifies this beast as Christendom coming out of the "sea" which is Christendom, which believes in the trinity, with it's counterpart, the Lamb-Dragon Beast, not marked with the "666" coming out of the "earth" thus representing the "true worship" temple organization with better, more Biblically established beliefs and thus Jehovah's Witness organization GB (also called the "false prophet"). But the naming of this beast with the 666 certainly demonstrates that even in the Bible the trinity doctrine would be one that would infiltrate well into the Christian belief system for the most part, though at the same time, condemning it as a false doctrine. Thus the 6-6-6 is another "trinity" worth noting.
Thanks, again, for your research. I think I'm going to post something separate about Artemis and Song of Solomon now that I've gotten some good photo links.!!!
JC