OP, you asked:
But, whereas Adam was the Father of all mankind, why then is Jesus never called our Father? Why do the Scriptures consistently refer to him as "the Son"?
First, God is the “father” of all by virtue of the fact that he is the Creator of the human family. Humanity was fashioned in his very image (Genesis 1:26-27)
Do we not all have one Father? Did not one God create us? Malachi 2:10<
he says: “we are also his offspring”
As also some of the poets among you have said, ‘For we are also His offspring.’ Therefore being offspring of God, Acts 17: 28-29<
Adam was of God.
of Enosh, of Seth, of Adam, of God
Adam became the father of Seth. That is the only time I see that Adam being mentioned as the father of anybody.
And after he had become the father of Seth,
Adam did represent all of mankind.
for even as in Adam all die, so also in the Christ all will be made alive, 1 Corinthians 15:22<
And He made from one man every nation of men, to dwell upon all the face of the earth, having determined the appointed times and the boundaries of their habitation,
Second part of your question is why is Jesus never called our father.
First of all God is the father of Christ.
Blessed be the God and Father of our Lord Jesus Christ, the Father. 2 Corinthians 1:3<
We are created in Christ.
For we are His workmanship, having been created in Christ Jesus for good works which God prepared beforehand that we should walk in them.<
Christ is not our Father , But God is our father.
'I am ascending to My Father and your Father, and to My God and your God.' John 20:17<
The third part of your question.
Why do the Scriptures consistently refer to him as "the Son"?
In the very beginning a seed was promised to Eve. She would be called the mother of all the living because of this seed.
The Son is the Seed.
I will put enmity between you and the woman,
and between your seed and her seed.
He will crush your head,
and you will strike his heel.
We know the seed was again promised through Abraham.
“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” (Galatians 3:16).<
This is the true seed of God, coming in the form of the son of man.
it has been written: “The first man Adam became into a living soul;”the last Adam into a life-giving spirit.
However the spiritual was not first, but the natural; then the spiritual. The first man was made of dust from the earth, the second man from heaven. As the one was made of dust, so also are those of the earth; and as is the heavenly one, so also are those of heaven. And as we have borne the image of the earthly, we shall also bear the image of the heavenly.
1 Corinthians 15: 45-49<
Unless a seed falls to the ground and dies, it abides alone.<
The hour has come for the Son of Man to be glorified. truly, I say to you, unless a grain of wheat falls into the earth and dies, it remains alone; but if it dies, it bears much fruit.<
You fool! What you sow does not come to life unless it dies
1 Corinthians 15:36<
The seed died in the form of a man , a natural body, and a new creation spring forth.
It is sown a natural body; it is raised a spiritual body. If there is a natural body, there is also a spiritual body. So it is written: “The first man Adam became a living being;”e the last Adam a life-giving spirit
First Corinthians 15:44<
And God said let us make man in our image, it seems like it was a twofold process. The true Son of God was revealed in Christ. Those in Christ now are a brand new creation where God is our t
Father as well. No grand parent here .
If anyone is in Christ, he is a new creation.The old has passed away. Behold, the new has come!
2 Corinthians 5:17<
It was through the Son of God, that became the son of man, that died, that became a brand new creation. He's now sent the spirit of his son into our hearts.
For you have not received a spirit of bondage again to fear, but you have received the Spirit of divine adoption as sons, by whom we cry, "Abba! Father!" Romans 8:15<