REGENERATION

The fall for Blake is the dividing of man from God and from his brothers, his other selves. The fracture of the bond which joins God and man leads to the division into the four mighty ones, the Zoas.

The process must be reversed. The fall occurs in in discrete stages and regeneration recapitulates the process in reverse order. 

Jerusalem, Plate 7, (E 150)
"Los answer'd. Altho' I know not this! I know far worse than this:
I know that Albion hath divided me, and that thou O my Spectre,
Hast just cause to be irritated: but look stedfastly upon me:
Comfort thyself in my strength the time will arrive,
When all Albions injuries shall cease, and when we shall         
Embrace him tenfold bright, rising from his tomb in immortality.
They have divided themselves by Wrath. they must be united by
Pity: let us therefore take example & warning O my Spectre,
O that I could abstain from wrath! O that the Lamb
Of God would look upon me and pity me in my fury.                
In anguish of regeneration! in terrors of self annihilation:
Pity must join together those whom wrath has torn in sunder,
And the Religion of Generation which was meant for the destruction
Of Jerusalem, become her covering, till the time of the End.
O holy Generation! [Image] of regeneration!     
O point of mutual forgiveness between Enemies!
Birthplace of the Lamb of God incomprehensible!
Thou goest to Eternal Death & all must go with thee"

On page 216 of William Blake's Circle of Destiny, Milton O. Percival states:

"It goes without saying that regeneration must be in terms of unification. The severed Spectre and Emanation must unite as one. Man's discordant masculine and feminine selves must end their strife, and the female return to her original life of self-annihilation. 'Sexes' must cease to be. The warring Zoas who, as abstractions, became Gods with dominion over man, must once again take their places in Albion's bosom, servants to the only God the Divine Humanity. All distinctions between Albion and his universe must disappear. Man must come to see that 'everything that lives is holy.' The awakening Albion of Blake's myth

'... looks out in tree & herb & fish & bird & beast,
collecting up the scatter'd portions of his immortal body.'

The giant androgyne is being re-assembled.

In Blake's symbolism the sexual garments are exchanged for the human; the mortal disappears in the immortal, the natural in the spiritual, the corruptible in the incorruptible; fire is changed to light, night into day, and winter into spring. 
...

Wikimedia

Illustrations to Book of Job 
Plate 18, Linnell Set

In short, in Blake's regenerated world we have the familiar return of the mystic to a lost paradisaical state. Such a return implies the birth of the Son of God in the soul. This rebirth is imaged in the Job pictures by Job's appearance in the likeness of Christ. Albions regeneration necessitates a similar change, but with the universal liberation which the wider symbol signifies, the cosmos is also freed from the vanity laid upon it."

Job.42 

[1] Then Job answered the LORD, and said,

[2] I know that thou canst do every thing, and that no thought can be withholden from thee.
[3] Who is he that hideth counsel without knowledge? therefore have I uttered that I understood not; things too wonderful for me, which I knew not.
[4] Hear, I beseech thee, and I will speak: I will demand of thee, and declare thou unto me.
[5] I have heard of thee by the hearing of the ear: but now mine eye seeth thee.
[6] Wherefore I abhor myself, and repent in dust and ashes.
...
[9] So Eliphaz the Temanite and Bildad the Shuhite and Zophar the Naamathite went, and did according as the LORD commanded them: the LORD also accepted Job.

This is the text on Plate 18 of Blake's engraving. 

From Encounter with the Self, by Edward F. Edinger:

"Job is a sacrifice for Yahweh's developing consciousness. At first he is an involuntary victim. After the theophany, when he sees the reality of Yahweh with his own eyes, he takes on the attitude of voluntary sacrifice:

'I had heard of thee by the hearing of the ear,
but now my eye sees thee;
therefore I despise myself,
and repent in dust and ashes.'

Job's comforters are no longer separated from him. The sacrificial attitude brings unity to the personality as ego, shadow figures and wife-anima turn toward the center which they serve and which unites them."