Hi Qoheleth,
I've read through the thread, but sometimes in reading a long line of posts, I miss things, so if I repeat something that has already been gone over, forgive me.
In response to your original question, "The parts of the text in bold are the Comma Johanneum, and are the basis of the 3 in 1 doctrine. Yet since it was not in the original texts is it right not to question the 3 in 1 doctrine and believe it wholeheartedly?"
I don't think that God minds us questioning anything...as long as we are questioning with the idea of truly arriving at His truth and not questioning in order to promote our own ideas and agendas.
As for the Comma Johanneum, I don't know of very many Christians that point to this text as the "basis" of the 3 in 1 doctrine. More often, people look to the Gospel of John, the way that Father, Son and Holy Spirit refer to each other and the eternal nature of Jesus as the basis of the Trinity. I know you've looked at Psalm 2, which is a very clear text regarding the Divine nature of the Son who is separate of the Father...but only for those who believe that the New Testament is every bit as inspired and infallible as the Old Testament, which you do not. Yet I do wonder how you explain “I will surely tell of the decree of the LORD:
He said to Me, ‘You are My Son, Today I have begotten You" as being about Israel?
I'm assuming from your user name and the respect with which you hold the Old Testament that you are a believing Jew (please correct me if I'm wrong)...so I'll try to point out the various texts in the Old Testament that shows that the Son is both distinct from the Father and divine Himself.
But, as theLords pointed out... we really haven't come to a basic understanding of the actual teaching of the Trinity. Something that should be done. For now, suffice it to say that the Trinity is not a doctrine that teaches a plurality of Gods...as a matter of fact, this is what sets Christians apart...the fact that we believe wholeheartedly that God is indeed One...there is only One God...but that He has revealed Himself to be Father, Son, and Holy Spirit, three distinct persons, but One God.
Yes, it is confusing...however as the Old Testament prophet said, "For My thoughts are not your thoughts, Nor are your ways My ways," declares the LORD." Both Christians and Jews need to be satisfied at times that God certainly doesn't always reveal things about Himself, nor about how He operates...and we all should certainly be able to admit that there are going to be truths about God that we, in our finite minds, are never going to be able to fully comprehend about God, even when He does reveal them to us.
Now, as for Old Testament texts that point to the Trinity.... Here is the thing...these texts were, for ages, understood in one way only. However, with the coming of the Son and His pouring His Spirit out on all of His people, there is a newer understanding of what these texts mean.
For instance, with Psalm 45, the psalm can be looked at as merely a song of praise, possibly to Solomon, or perhaps to God. But then, the psalmist writes:
Your throne, O God, is forever and ever;
A scepter of uprightness is the scepter of Your kingdom.
You have loved righteousness and hated wickedness;
Therefore God, Your God, has anointed You
With the oil of joy above Your fellows.
What does this mean, to be referring to God, then say "Therefore God, Your God, has anointed You..."
For us Christians, who have the Spirit, we understand that this is a text in which the Father is speaking of the Son. This is one of the instances in the Old Testament where the nature of the Son is revealed, even though not yet fully understood at the time of the writing.
Other such passages include Genesis 1 itself in which God says, "Let Us make man according to our image..." I know many non Christians who believe that this is referring to God speaking to the angels...but the angels are not capable of creating and therefore God would not have been speaking to them. Only God is the creator, so it stands to reason that God is speaking to a creator...Yet, if God is One there is only one creator...none of it makes any sense whatsoever, unless and until one sees that the Father, Son and Spirit all worked to create...All One God, yet the Father says to the Son and Spirit, "Let Us..."
Micah 5 is yet another text which Christians look to that reveals the Divine nature of Jesus the Son...
“But as for you, Bethlehem Ephrathah,
Too little to be among the clans of Judah,
From you One will go forth for Me to be ruler in Israel.
His goings forth are from long ago,
From the days of eternity.”
The only way one can be "going forth...from the days of eternity" is if one is God or one is an angel. Certainly human beings are not capable of going forth from the days of eternity, for we all were born and all die.
Christians see this passage as one that describes the Divine nature of the Son and view this as a prophesy of Jesus' birth in Bethlehem.
This post is getting pretty long... if you're truly interested in learning about the Trinity and why the Comma Johanneum is not the basis of the doctrine, I'll spend more time looking at the various OT passages.