Trying to separate God always brings issues. JLB is right, that every showing/engagement of God in the O.T. is a showing of The Son, His Image, His Word, His Spirit. They are One so it's always problematic trying to divide them when there is no them plural in/as One.
Manifestations may be more accurate.
Titus 3:4
But after that the kindness and love of
God our Saviour toward man
appeared,
1 Timothy 3:16
And without controversy great is the mystery of godliness:
God was manifest in the flesh, justified
in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory.
God was also manifest in the O.T. via the Spirit of Christ, the Spirit of annointing. What we have as "Word of God" in the O.T. is actually a manifestation of Jesus Christ, The Word. Regarding the speakings of the prophets Peter notes thusly:
1 Peter 1:11
Searching what, or what manner of time
the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow.
Where we read of God as YHVH we are seeing the manifestation of God, The Word, Jesus Christ. There was no other God or separate God or different God in the O.T.
The Word of God in the O.T. is the same Word of God in the N.T.
This is Oneness, it's wrong. Oneness assumes Jesus is the literal spiritual word of some type of god machine. There is also seperation you claim is not there.
Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;
(Heb 1:2 KJV)
Also 1 Tim 3:16 God was manifest in the flesh is a known KJV exclusive. This text only appears after the 4th century, when Trinity came into being. The KJV was good at changing text to support Trinity. It's in no known early text.
Latin Vulgate
et manifeste magnum est pietatis sacramentum quod manifestatum est in carne iustificatum est in spiritu apparuit angelis praedicatum est gentibus creditum est in mundo adsumptum est in gloria
Quod Manifestatum. He manifested.
However:
1Jn_4:2 Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:
It was the Son that came in the flesh. The one that had always been with the Father.
Joh_17:5
And now, O Father, glorify thou me with thine own self with the glory which I had with thee before the world was.
However, the Father did Call him God.
There is not one, but two.
Trinity never makes them one in scripture. It's a mystery of Christian faith.
Oneness is a confused mess invented in 1914
Jesus is one in the Father, be we are one in him. Don't make us the Father though.
The Word was made flesh, the only begotten of the Father. Just means what God spoke in Psalm came to pass, does not make Jesus some part of a word god system.
Act_13:33
God hath fulfilled the same unto us their children, in that he hath raised up Jesus again; as it is also written in the second psalm, Thou art my Son, this day have I begotten thee.
Jesus came from the spoke word, it came to pass, we are also born of the Word of God, but that don't make us the Father Either.
For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
(Isa 9:6 KJV)
The mighty El, the KJV switched this. Jesus is the Father of eternity as we are born through him.
For a Child hath been born to us, A Son hath been given to us, And the princely power is on his shoulder, And He doth call his name Wonderful, Counsellor, Mighty God, Father of Eternity, Prince of Peace.
(Isa 9:6 YLT)
Isa 9:7 Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever.
The zeal of the LORD of hosts will perform this.
The Lord God performed that, crucified his son, Sent His son to the Earth.
Jesus was the image of His Father, the firstborn of many, has always been with the Father, is not some Word part of the Father or some strange morph of the Father.
Jesus has His own throne, is God the Son, is not His Father else we don't have an advocate. Is the King of Kings.
There is only one Lord God. The one that made everything, the One Jesus said is greater than him.
Jud_1:4 For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying
the only Lord God, and our Lord Jesus Christ.
There is only ONE Lord God, none like him, many like His image and in his god class, but none equal to.
Every single scripture must be taken into account and they all must match perfect.
Be blessed.