I don’t know of anyone who believes that Jesus is a “secondary God”......but no scriptures teaches that Jesus is Almighty God, Yahweh. The trinity actually teaches that there are three equal “gods”...”God the Father”, “God the Son” and “God the Holy Spirit”.....I can find “God the Father”, but not once are the other two ever mentioned.
The apostles did not think that Jesus was their God....
1 Corinthians 8:5-6...here Paul speaks on behalf of his fellow Christians.....
“For even though there are so-called gods, whether in heaven or on earth, just as there are many “gods” and many “lords,” 6 there is actually to us one God, the Father, from whom all things are and we for him; and there is one Lord, Jesus Christ, through whom all things are and we through him.”
The fact that there are “many gods and many lords” means that these titles apply to more personages than just Yahweh and his Christ. Even satan is called a “god” in 2 Corinthians 4:4.
The very passage that you quote from, which has been corrupted at a very early time, actually disproves what you say, "but no scriptures teaches that Jesus is Almighty God, Yahweh"
On the contrary, we have here ONE GOD, or Elohim, Who Paul says, is the Father. he then says, there is ONE LORD, which is YAHWEH, and this is Jesus Christ. This is clear from Isaiah 45:5, which reads, "I am Yahweh, and there is none else. Besides me, there is no god". Jesus Christ is the ONE LORD, which means that Paul here distinguishes Elohim, the Father, from Yahweh, Jesus Christ!
“But to us one God, the Father, of Whom all things, and we in Him; and one Lord Jesus Christ, by Whom all things, and we by Him.
And one Holy Spirit, in Whom all things and we in Him” (Original Letter by The Apostle Paul)
The words, “καὶ ἐν πνεῦμα ἅγιον, ἐν ᾧ τὰ πάντα καὶ ἡμεῖς ἐν αὐτῷ”, were removed at a very early time. Like 1 John 5:7, which also very clearly Testifies to the Holy Trinity.
Greek Manuscript
Uncial 0142, 10th century of the Byzantine text-type (Dr A Souter Novvm Testamentvm Graece.1962)
Minuscule 460, 11th century (Souter; Expositors Greek Testament), dated by F Scrivener
Minuscule 618, 12th century of the Byzantine text-type (Souter; EGT)
Minuscule 234, 13th century of the Byzantine text-type (Souter; EGT)
ATHANASIUS (293-373) – Greek
“As
it is thus written, it is clear that
the Spirit is not a creature, but takes part in the act of creation. The Father creates all things
through the Word in the Spirit; for where the Word is, there is the Spirit also”
HILARY OF POITIERS (315-368) – Latin
“For God the Father is One, from Whom are all things; and our Lord Jesus Christ the Only-begotten, through Whom are all things, is One; and the Spirit, God's Gift to us, Who pervades all things, is also One” (On the Trinity (Book II, ch.1)
Although Hilary, who was a close friend of Athanasius, does not use “in Whom all things”, that fact is that he does refer to the Holy Spirit in this context, which is clearly from 1 Corinthians 8:6. The words are a free quote, as we have “the only-begotten”, etc, here for Jesus.
EPIPHANIUS OF SALAMIS (315-403 - Greek
According to Nestle-Aland's Novum Testamentum Graece (26th edition)
GREGORY OF NAZIANZUS (329-389) – Greek
“For to us there is but One God, the Father, of Whom are all things, and One Lord Jesus Christ, by Whom are all things; and
One Holy Ghost, in Whom are all things” (Oration XXXIX, ch.xii)
BASIL THE GREAT (330-379) - Greek
“in the words of the Apostle, "One God and Father of whom are all things,...and one Lord Jesus Christ by whom are all things." 1 Corinthians 8:6 "Whatever, then," he goes on, "is the relation of these terms to one another, such will be the relation of the natures indicated by them; and as the term 'of whom' is unlike the term 'by whom,' so is the Father unlike the Son." On this heresy depends the idle subtlety of these men about the phrases in question. They accordingly assign to God the Father, as though it were His distinctive portion and lot, the phrase “of Whom;” to God the Son they confine the phrase “by Whom;” to
the Holy Spirit that of "in Whom,"” (De Spiritu Sancto, Chap. 2)
AMBROSE OF MILAN (339-397) – Latin & Greek
“So, then, as we read that all things are of the Father, so, too, that all things can be said to be of the Son, through Whom are all things; and we are taught by proof that all things are of
the Spirit in Whom are all things” (On The Holy Spirit, Bk.2, ch.9. 96)
AUGUSTINE OF HIPPO (354-430) – Latin & Greek
“God, not only the Father, but also the Son and
the Holy Spirit, “of whom are all things, and through whom are all things, and
in whom are all things” (On the Trinity, chapter XV. 25)
“Of whom are all things, through whom are all things,
in whom are all things” (On the Origin of the Soul, Bk.I, ch. 24)
“from whom are all things, by whom are all things,
in whom are all things” (Against Two Letters of the Pelagianas, Ch. 16)
CYRIL OF ALEXANDRIA (died 444) - Greek
According to Dr Souter, and The Expositor's Greek Testament.
JOHN OF DAMASCUS (675-749) – Greek
“But to us there is but one God, the Father, of Whom are all things, and one Lord Jesus Christ, through Whom are all things, and
one Holy Spirit, in Whom are all things” (Exposition of the Orthodox Faith, Chapter X)
FIFTH GENERAL COUNCIL AT CONSTANTINOPLE, 5 MAY A.D.553
“If anyone shall not confess that the nature or essence of the Father, of the Son, and of the Holy Ghost is one, as also the force and the power; [if anyone does not confess] a consubstantial Trinity, one Godhead to be worshipped in three subsistences or Persons: let him be anathema. For there is but one God even the Father of whom are all things, and one Lord Jesus Christ through whom are all things, and
one Holy Spirit in whom are all things” (The Capitula of the Council, The first "anathema”)
At the Council held in A.D.553, the then Emperor, Justinian I, sought to settle once and for all, the dangers of “Monophysitism”. At this Council, there were some 164 Bishops, who were mainly of the Greek speaking Church, with about 68 who were from the North African Church, which was mainly Latin speaking. Without going into too much detail of what took place at this Council, we shall look at one section of a document that was the outcome of this Council. We are told that “a series of 14 articles, or anathemas, was prepared, most of them corresponding closely with the articles of Justinian's 'confession of faith', in which the orthodox faith as to the Trinity and Incarnation was restated” (Dr H Wace, and W Piercy; A Dictionary of Christian Biography, p.612)
The evidence to the Holy Spirit in 1 Corinthians 8:6, is in my opinion, very strong. Its omission is no doubt due to the corruption by those who were enemies to the Bible Teaching on the Holy Spirit.