In the priesthood order "of Melche", the head of a "house" is the "firstborn", "father", "king", "chief", "priest," "provider," "protector."
The house of Adam is "us" -all we who are born in Adam; but our head is dead in spirit, and is not alive to be our living continuing "firstborn", "father", "king", "chief", "priest," "provider," "protector."
Jesus Christ is the Head of the New Man house, the second Man created and the "Last Adam", and if we are not born again, by the adoption into His One Living Spirit, which is called the "regeneration" by Paul, which is the New Birth, then we are not in the New Man in Spirit, not made one in Him, and we will not then be regenerated [reborn] in the New Man body, in the image of the Last Adam and second Man.
The Church is the House of God, which is the Congregation of those reborn into Him.
Israel, the people, was called the "House of God" as Israel is His New Man name -Isaiah 49, which He gave to Jacob as a sign of the adoption to come -in Spirit and body, which Abraham had got the sign of the promise of in the name chnge.
Adoption into His Spirit by being joined to His Spirit is the New or "second birth" that all who will have Him as "Head" must come to.
In Adam all die, in Christ all are made alive -whosoever will.
Gen 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.
2 Samuel 22
44 "
You have also delivered me from the strivings of my people;
You have kept me as the head of the nations.
A
people I have not known shall serve me.
45 The foreigners submit to me;
As soon as they hear, they obey me.
46 The foreigners fade away,
And *come frightened from their hideouts.
47 "The Lord lives!
Blessed
be my Rock!
Let God be exalted,
The Rock of my salvation!
48 It is God who avenges me,
And subdues the peoples under me;
49 He delivers me from my enemies.
You also lift me up above those who rise against me;
You have delivered me from the violent man.
50 Therefore I will give thanks to You, O Lord, among the Gentiles,
And sing praises to Your name.
51 He is the tower of salvation to His king,
And shows mercy to His anointed,
To David and his descendants forevermore."
Isa 55:3 Incline your ear, and come unto me: hear, and your soul shall live
; and I will make an everlasting covenant with you, [even] the sure mercies of David.
Act 13:34 And as concerning that he raised him up from the dead, [now] no more to return to corruption, he said on this wise, I will give you the sure mercies of David
Saul heard the convicting Word of God preached by Jesus' witness, Stephen, and the conviction was so powerful he could not shake it; and then the Risen LORD of Glory came to him powerfully, and said... "it is hard for you to rebel against the convictions".
Paul was converted to Jesus Christ by the witness of Stephen, anointed by the Holy Spirit to Saul's heart; he could not shake it until He was met, and conquered by His love -and to Paul, that day, the revelation of the birth into Christ by His Spirit of regeneration was granted.
Paul met the Hidden Son of Man by the revelation promised in Enoch to the "elect", who choose to live the "elect life and to whom He would be revealed.
That "Head of Days" seen by Enoch, is that Son of Man come in New Man flesh who granted to Paul the Revelation of Himself.
That encounter was a regeneration of Spirit for the Pharisee, Saul.
the Ancient of Days whom Daniel saw is the same Head of days whom Enoch saw, who is now come in human flesh of the second creation but who existed from the beginning as that One to come, whom Enoch saw, "Hid -concealed- in God.
Isaiah 9:15 gives us this about the Ancient of Days as the Head of Days, in speaking about the "head" of Israel being cut off [the prophets]
"The ancient and honourable, he [is] the head;"