You have two points of discussion here. The relationship between the Father and Son. And about the Son.This is the church wrong view. The think that the Holy Spirit is another being, they have failed to realize that the Holy Spirit is Jesus Himself. Thatd why when Jesus was on earth the Holy Spirit was in the Father. And when Jesus ascended to heaven He have poured out His Holy Spirit to the people and apostles who was worshipping God by the pentecost. The Holy Spirit is their power.
In regard to the firstborn of all creation.
The fullness was pleased to dwell IN Him. -From the will of another at a point in history.
Jesus is ALL that the Father is. The image of the invisible God.
So my answer to your question, "Is Jesus God?"
He never dies.
Yes, He is all that the Father is.
No, He has always been the Son.
The Spirit of the Father is living IN Jesus.
They are on in that manner.
Jesus taught that.
I don't believe this was/is the Holy Spirit or the Spirit of the Father.
"Father into your hands I commit My Spirit"
And "Jesus" calls the Father the only true God. If He always was and always was God how does that believe in "one" God?
Jesus as a Son has His own Spirit and the Spirit of the Father lives in Him. They are one in that manner.
Let us make man in our image and in our likeness.
The Son, who was and is, is a being a person.
A body was prepared for Him and the Son who was, His Spirit, was in the tent of that body.
And the Spirit of the Father was living in Him doing His work.
My spirit is not in me it is me.
The Spirit of God is not in the Father it is the Fathers own Spirit.
Jesus as the Son has His own Spirit and the Spirit of the Father is living in Him.
John 17 Oneness defined
I have given them the glory that you gave me, that they may be one as we are one— I in them and you in me—so that they may be brought to complete unity. Then the world will know that you sent me and have loved them even as you have loved me.