Speaking of Jesus as the Son of God, the apostle Paul explains:
For by him were all things created, that are in heaven, and that are in earth, visible and invisible, whether they be thrones, or dominions, or principalities, or powers: all things were created by him, and for him: And he is before all things, and by him all things consist. (Colossians 1:16-17 kjv)
Just as every man and woman today is of the same essence and nature of their father, man, so the Word of God, who came forth from the Father, and who existed with the Father from eternity, is of the same essence and nature as the Father (God). Likewise, every man and woman that has ever lived, and will live, was in Adam from the beginning:
"For as in Adam all die, even so in Christ shall all be made alive." (1 Corinthians 15:22)
We are born in sin, dead to God, because we were in Adam when he sinned. His genes are our genes. Even though we had no consciousness and, indeed, were not fashioned until the time our immediate fathers and mothers produced the life that germinated in the womb, we were still reckoned as in Adam by God.
In a similar manner the Word of God existed from eternity within the Father and came forth from the Father:
"For the Father himself loveth you, because ye have loved me, and have believed that I came out from God. I came forth from the Father, and am come into the world: again, I leave the world, and go to the Father." (John 16:27-28 kjv)
There is no explaining the Godhead beyond this. Nor do I profess to know anything about the Godhead beyond what the Scriptures have revealed. Theologians may argue back-and-forth about the meaning of the Trinity, or any other concept of God, but we cannot go beyond the Sctiptures.
What we do know is that the Word of God, who became the man Jesus of Nazareth, is God in the flesh:
"In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him; and without him was not any thing made that was made. In him was life; and the life was the light of men. And the light shineth in darkness; and the darkness comprehended it not. There was a man sent from God, whose name was John. The same came for a witness, to bear witness of the Light, that all men through him might believe. He was not that Light, but was sent to bear witness of that Light. That was the true Light, which lighteth every man that cometh into the world. He was in the world, and the world was made by him, and the world knew him not. He came unto his own, and his own received him not. But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: Which were born, not of blood, nor of the will of the flesh, nor of the will of man, but of God. And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth." (John 1:1-14 kjv)
The Word of God became the "Son of Man" in the flesh. Through the virgin birth He acquired the unique anointing as the only-begotten Son of God. All things were created by Jesus Christ, who existed as the Word of God in the beginning with the Father. He came forth from the Father.
"Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned: (For until the law sin was in the world: but sin is not imputed when there is no law. Nevertheless death reigned from Adam to Moses, even over them that had not sinned after the similitude of Adam's transgression, who is the figure of him that was to come. But not as the offence, so also is the free gift. For if through the offence of one many be dead, much more the grace of God, and the gift by grace, which is by one man, Jesus Christ, hath abounded unto many. And not as it was by one that sinned, so is the gift: for the judgment was by one to condemnation, but the free gift is of many offences unto justification. For if by one man's offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.) Therefore as by the offence of one judgment came upon all men to condemnation; even so by the righteousness of one the free gift came upon all men unto justification of life. For as by one man's disobedience many were made sinners, so by the obedience of one shall many be made righteous. Moreover the law entered, that the offence might abound. But where sin abounded, grace did much more abound: That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord. Romans 5:12-21 kjv