>>But isn't it a given that Moses promoted monotheism?<<
It's only a given if you choose to accept what others have taught and understood it (Deut 6:4) to mean. I accept neither orthodoxy (triune) or JW and others (Arianism/singularity). I understand the Bible to fully communicate duotheism.
Deut 6:4
4 Hear, O Israel: The LORD our God, the LORD is one.
You see that text above? The word "one" in Hebrew can have two meanings. The first meaning is the numeral one. The second meaning is one as in union. How can I know which way is correct? One text (of many) that helped me decide was the following:
John 10:29-30
30 I and the Father are one." (the LORD is one <unified>)
When someone with an open mind reads such words as the above from Jesus, it certainly adds weight that the "ONE" spoken of in Duet. 6:4 means unification and NOT a numerical singularity ie monotheism.
Consider this:
I (The Holy) and the Father (The Most Holy) are one (Temple).
Rev 21:22
22 I did not see a temple in the city, because the Lord God Almighty and the Lamb are its temple.
The temple and the tabernacle fully represented God, as can be seen by this text in Revelation. Well, that symbol was one tent with two rooms. One God consists of two beings. Just as man consists of two beings.
Man = Man and Woman
God = Father and Son
The physical counterparts below reflect the realities in heaven above.
TWO seperate rooms but ONE tabernacle/temple.
The two become one flesh.
pom