Did Paul change his teaching regarding Jesus? Rom 9:5

No, the Apostle Paul did not change his mind as it pertains to "Who is Jesus Christ." In fact, he reinforced his position that Jesus Christ was God, just read all of his writings.

Let's examine the "trained eye" of Greek Scholar A.T. Robertson here:

Verse 5 Of whom (εξ ων). Fourth relative clause and here with εξ and the ablative.

Christ (ο Χριστος). The Messiah.

As concerning the flesh (το κατα σαρκα). Accusative of general reference, "as to the according to the flesh." Paul limits the descent of Jesus from the Jews to his human side as he did in Romans 1:3.

Who is over all, God blessed for ever (ο ον επ παντων θεος ευλογητος). A clear statement of the deity of Christ following the remark about his humanity. This is the natural and the obvious way of punctuating the sentence. To make a full stop after σαρκα (or colon) and start a new sentence for the doxology is very abrupt and awkward. See Acts 20:28; Titus 2:13 for Paul's use of θεος applied to Jesus Christ.

Now, here is what you stated, "They are not both God anywhere except for passages like Rom 9:5." No, I can provide many verses that confirm that Jesus is God. Acts 20:28, Titus 2:13, John 20:28, 2 Peter 1:1 and others.

The problem that you have by you quoting, 1 Cor 1:3,3, Rom 1:7, Gal 1:1, and Eph 1:3 is the fact that you do not know how to "RECONCILE" verses that "appear" to contradict each other.

You look at Jesus Christ as a man only and disregard the verses that say He is God in flesh. I most all the time quote verses in context. For example, I have given you Philippians 2:5-8 that explicitly says at vs6 Jesus existed as God who then took the form of a man. What is so hard to understand about this?

Paul, formerly known as Saul, certainly changed his view of God when he changed from pre-believer to believer. But did Paul change his mind, his teaching, about God post believer? No.

Paul is quite explicit as he uses the terms God the Father and Jesus His Son and our Lord. The OP quotes a number of examples. But this isn't the end of the story.

I suppose for anyone to believe God dwelt among us is a radical departure from the idea God is somewhere "out there" to God is right here. This idea, however, was foreshadowed. But is that the "same" thing? Is Jesus who dwelt among us God or not? Without going into Christology, here is the idea.

So shall ye know that I am the LORD your God dwelling in Zion, my holy mountain: then shall Jerusalem be holy, and there shall no strangers pass through her any more. Joel 3:17

Paul knows his scripture. He knows God will dwell among us and further only God is the Saviour.

For I am the LORD thy God, the Holy One of Israel, thy Saviour: I gave Egypt for thy ransom, Ethiopia and Seba for thee. Isa 43:3

I, even I, am the LORD; and beside me there is no saviour. Isa 43:11

Verily thou art a God that hidest thyself, O God of Israel, the Saviour. Isa 45:15

Yet I am the LORD thy God from the land of Egypt, and thou shalt know no god but me: for there is no saviour beside me. Hos 13:4

No Saviour, but the LORD our God. The only one.

Paul also helped write scripture in which he makes clear that Jesus is the Saviour.

To Titus, mine own son after the common faith: Grace, mercy, and peace, from God the Father and the Lord Jesus Christ our Saviour. Titus 1:4

For our conversation is in heaven; from whence also we look for the Saviour, the Lord Jesus Christ: Phil 3:20

And as the Saviour is God. Is this explicit? Yes.

Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; Tit 2:13

For therefore we both labour and suffer reproach, because we trust in the living God, who is the Saviour of all men, specially of those that believe. 1 Tim 4:10

So, did Paul change his teaching while a Christian, no? Did he explain concepts foreign to nearly everyone? Yes.

Grace be to you and peace from God the Father, and from our Lord Jesus Christ, Gal 1:3

But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law, Gal 4:4

Not purloining, but shewing all good fidelity; that they may adorn the doctrine of God our Saviour in all things. Titus 2:10

No, we do not think that the Apostle Paul changed his mind about Jesus following his Damascus road conversion. Obviously, that was a big changing point.

YLT, KJV, and most other "good" translations read the way the second example reads:

whose are the fathers, and of whom is the Christ, according to the flesh, who is over all, God blessed to the ages. Amen.

The "who is God over all" translation may or may not be theologically offensive but it is not a good rendering of the text.

Paul is referring to how God has, at all times, blessed or "spoken well of" the Christ. The most important part of this verse is that the Christ is of the Jewish fathers according to the flesh. The preposition κατα (kata) is rendered here and indicates a motion downward:

The preposition κατα (kata) expresses a motion downward. Tied to appropriate verbs it usually describes motion down from a higher place or down to a lower place. It may be used in the sense of "bearing down upon", that is an aiming for a certain place or even a certain understanding, when something "comes down" to something. Our word may also refer to something in the sense of "in respect of" or "on account of" or "by means of".

The use of this preposition does not dictate that the Christ existed prior but it does not exclude the possibility either. "Proof-texting" has it's place in theological development but the amalgamation of proof texts can always be harmful when over-arching context is ignored. Much of the "proof- texts" which appear to defend the mere humanity of Christ should be understood as speaking of Christ "according to the flesh" rather than "fully defined as flesh".

The tent of meeting was given as the place on earth where God would dwell with His people. This tabernacle was patterned after a heavenly reality...it was, in all of it's aspects, a type and Jesus is the antitype in all of those aspects. His body is the temple (John 2:19-21), his flesh is the veil of separation which was torn (Hebrews 10:19-20), he is the only way to the Father (John 14:6), etc.

God has promised to dwell among His people in a physical sense. The first physical temple was a picture of the physical temple to come:

And there I will meet with the children of Israel, and the tabernacle shall be sanctified by my glory. And I will sanctify the tabernacle of the congregation, and the altar: I will sanctify also both Aaron and his sons, to minister to me in the priest's office. And I will dwell among the children of Israel, and will be their God. And they shall know that I am the LORD their God, that brought them forth out of the land of Egypt, that I may dwell among them: I am the LORD their God. - Exodus 29:43-46

Moreover I will make a covenant of peace with them; it shall be an everlasting covenant with them: and I will place them, and multiply them, and will set my sanctuary in the midst of them for evermore. My tabernacle also shall be with them: yea, I will be their God, and they shall be my people. And the heathen shall know that I the LORD do sanctify Israel, when my sanctuary shall be in the midst of them for evermore. - Ezekiel 37:26-28

And Jesus the Christ is the fulfillment of this typological imagery of tabernacle and sanctuary: His flesh was the temple wherein God dwelt and walked among us. God, who is Spirit, dwelling within a sanctuary of flesh (named Jesus) so that He might dwell among us. Emmanuel, God with us.

The Apostle Paul did once regard Christ "according to the flesh" but came to the point where he no longer did so and we are encouraged in the same vein for to consider Christ according to the flesh only is a failure to fully apprehend Christ:

Wherefore henceforth know we no man after the flesh: yea, though we have known Christ after the flesh, yet now henceforth know we him no more. - 2 Corinthians 5:16

Any amalgamation of proof texts must obey this over-arching context and be informed by it. Thus a trinitarian or binitarian may view the rendering "the Christ, who is God over all" with the understanding that it is not actually the best rendering, while at the same time acknowledging this nod to the larger context.