Thanks for your question.
Hebrews 1:5 For unto which of the angels said he at any time, Thou art my Son, this day have I begotten thee? And again, I will be to him a Father, and he shall be to me a Son?
Hebrews 1:13 But to which of the angels said he at any time, Sit on my right hand, until I make thine enemies thy footstool?
Jesus did not physically exist before he was born of Mary.
1Peter 1:20 Who verily was foreordained (Greek ‘proginosko’ foreknown) before the foundation of the world, but was manifest in these last times for you,
It is the same word as that used of all who will be sons (and daughters) of God.
Romans 8:29 For whom he did foreknow (Greek ‘proginosko’ foreknow), he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.
The same word is used in Acts 26:5 (knew); Romans 11:2 (foreknew); 2Peter 3:17 (know these things before).
His pre-existence was only in the sense that he existed in the plan and purpose of God before the creation of the world.
At creation God gave Adam freewill and knew beforehand that he would fail to obey the one law he was commanded to keep.
As Adam was made ‘very good’ the temptation to disobey had to come from outside of himself.
Hence the serpent, with animal reasoning (an animal has no moral understanding), deceived Eve; and Adam chose to disobey.
Death for Adam and his offspring was the result until one would come who did no sin.
Jesus is a son of Adam.
His coming into existence was in the promise made in Eden concerning the seed of the woman who would destroy sin (in a metaphor bruise the head of the serpent).
Genesis 3:15 And I will put enmity between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel.
Eve was the mother of all living (Genesis 3:20)
So Christ was also the seed or offspring of Adam through Eve.
He was the last Adam who succeeded by obedience where the first failed by disobedience. He is the firstborn of God's new creation as Adam was the firstborn of the old creation.
1Corinthians 15:22 For as in Adam all die, even so in Christ shall all be made alive.... 45 And so it is written, The first man Adam was made a living soul; the last Adam was made (by resurrection from the dead) a quickening spirit.
Romans 5:19 For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous.
Christ’s genealogy through Mary in Luke is taken right back to Adam.
Luke 3:38 Which was (the son) of Enos, which was (the son) of Seth, which was (the son) of Adam, which was (the son) of God.
Jesus is a son of Abraham.
If Christ was to be the offspring of Abraham he had to come into being after Abraham. Abraham knew there was a saviour promised in Genesis 3:15.
John 8:56 Your father Abraham rejoiced to see my day: and he saw it, and was glad.
Abraham saw the coming of Christ with the eye of faith. Abraham was promised that this saviour would come through him.
Genesis 22:18 And in thy seed shall all the nations of the earth be blessed;
Of which Paul comments
Galatians 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
Jesus is a son of David.
Christ was also the seed promised to David.
1 Chronicles 10:11 And it shall come to pass, when thy days be expired that thou must go to be with thy fathers, that I will raise up thy seed after thee, which shall be of thy sons; and I will establish his kingdom. 12 He shall build me an house, and I will stablish his throne for ever. 13 I will be his father, and he shall be my son: and I will not take my mercy away from him, as I took it from him that was before thee: 14 But I will settle him in mine house and in my kingdom for ever: and his throne shall be established for evermore.
The identity is confirmed by Gabriel through Luke.
Luke 1:32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David:
Matthew’s opening statement
Matthew 1:1 The book of the generation of Jesus Christ, the son of David, the son of Abraham.
Jesus was sent from God in the same way that John Baptist was.
John 1:6 There was a man sent from God, whose name was John.
John did not pre-exist in heaven before he was born.
Jesus came into existence as a man. He was not ever an angel. He was made of a woman, flesh and blood.
Luke 1:31 And, behold, thou shalt conceive in thy womb, and bring forth a son, and shalt call his name JESUS.
Galatians 4:4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
Romans 1:3 Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;
Hebrews 2:14 Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death,
(The fulfilment of the promise made in Genesis 3:15 - sin has the power of death)
John is very pointed about believing that Christ came in the flesh.
1John 4:2 Hereby know ye the Spirit of God: Every spirit that confesseth that Jesus Christ is come in the flesh is of God:
3 And every spirit that confesseth not that Jesus Christ is come in the flesh is not of God: and this is that spirit of antichrist, whereof ye have heard that it should come; and even now already is it in the world.
2John 1:7 For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.
He was made under the Law of Moses so that he might fulfil it.
He was made with our nature to be tempted to sin exactly as we are.
Hebrews 4:15 For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin.
James 1:14 But every man is tempted, when he is drawn away of his own lust, and enticed.
Jesus refers to himself as the ‘son of man’ some 80+ times.
He uses it after his resurrection to the divine nature.
Luke 22:69 Hereafter shall the Son of man sit on the right hand of the power of God.
Stephen speaking by the Holy Spirit uses the same phrase.
Acts 7:56 And said, Behold, I see the heavens opened, and the Son of man standing on the right hand of God.
Paul uses the description man when speaking of Christ’s role as a mediator.
1Timothy 2:5 For there is one God, and one mediator between God and men, the man Christ Jesus;
Those in Christ are to be made ‘like him’.
Philippians 3:21 Who shall change our vile body, that it may be fashioned like unto his glorious body, according to the working whereby he is able even to subdue all things unto himself.
2 Peter 1:4 Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the divine nature, having escaped the corruption that is in the world through lust.
If Jesus inherited his nature from Mary what part of him was from God?
The answer must be his strength of character and purpose.
His will was different to his Father’s.
Luke 22:42 Saying, Father, if thou be willing, remove this cup from me: nevertheless not my will, but thine, be done.
He had the strength of character to bend his own will to conform to his Father’s will.
He conquered his own desires because he loved his Father more than himself.
He went to an agonising death because he loved us more than himself.
In this he was the character of God manifested in flesh.
God could not die for us so he did the next best thing. He fathered a son with our nature to die for us. Jesus was the only son begotten in this way.
When Philip asks Jesus to show them the Father he is asking for a vision of God’s glory as Moses did in the Mount Sinai.
John 14:8 Philip saith unto him, Lord, shew us the Father, and it sufficeth us.
Jesus’ reply is to leave us in no doubt that what he manifested was God’s character in the same way that God’s glory was announced to Moses.
John 14:9 Jesus saith unto him, Have I been so long time with you, and yet hast thou not known me, Philip? he that hath seen me hath seen the Father; and how sayest thou then, Shew us the Father?
Thomas finally connects the two for us.
John 20:28 And Thomas answered and said unto him, My Lord and my God.
And Paul explains
2Corinthians 5:19 To wit, that God was in Christ, reconciling the world unto himself, not imputing their trespasses unto them; and hath committed unto us the word of reconciliation.
The oneness of Christ and his Father is a oneness of purpose which is enjoined upon his followers.
John 17:11 And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
22 And the glory which thou gavest me I have given them; that they may be one, even as we are one:
The glory is the character and purpose.
John 1:14 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.
'Word' is not another name for 'Jesus' it is used of God's attributes manifested in Jesus.
I hope this helps,