Albion is the giant figure who represents Man. Blake’s myth consists of the life, death, and resurrection of Albion. The ‘heavenly Albion’ is One, the condition for which Jesus prayed in the Gospel of John 17:21.
However Albion fell, like Adam did in the Garden. He fell; we fell, everyone of us. Blake’s myth goes into great detail about how we fell. Albion fell essentially into four parts:
His head, heart, loins and body separated, became selfish and strove for dominion.
Blake called them Urizen, Luvah, Urthona (heavenly) or Los (carnally), and Tharmas.
The Eternal Man was a fourfold Unity; when Albion fell, it was into the four parts.
Blake called the four parts, the four zoas. His first very long poem had that name (although originally called ‘Vala’).
Each of the four zoas had an Emanation
Ahania was the emanation of Urizen
Vala was the emanation of Luvah
Enitharmon was the emanation of Los
Enion was the emanation of Tharmas
Prime biblical sources for the Four Zoas is found at Ezekiel 1 and Revelation 4 and 7.
4] And I looked, and, behold, a whirlwind came out of the north, a great cloud, and a fire infolding itself, and a brightness was about it, and out of the midst thereof as the colour of amber, out of the midst of the fire.
 Also out of the midst thereof came the likeness of four living creatures. And this was their appearance; they had the likeness of a man.
 And every one had four faces, and every one had four wings.
 And their feet were straight feet; and the sole of their feet was like the sole of a calf's foot: and they sparkled like the colour of burnished brass.
 And they had the hands of a man under their wings on their four sides; and they four had their faces and their wings.
 Their wings were joined one to another; they turned not when they went; they went every one straight forward.
 As for the likeness of their faces, they four had the face of a man, and the face of a lion, on the right side: and they four had the face of an ox on the left side; they four also had the face of an eagle.
 And before the throne there was a sea of glass like unto crystal: and in the midst of the throne, and round about the throne, were four beasts full of eyes before and behind.
 And the first beast was like a lion, and the second beast like a calf, and the third beast had a face as a man, and the fourth beast was like a flying eagle.
 And the four beasts had each of them six wings about him; and they were full of eyes within: and they rest not day and night, saying, Holy, holy, holy, Lord God Almighty, which was, and is, and is to come.
 And when those beasts give glory and honour and thanks to him that sat on the throne, who liveth for ever and ever,
Letter 23, to Thomas Butts, (E 722)
"Now I a fourfold vision see
And a fourfold vision is given to me
Tis fourfold in my supreme delight
And three fold in soft Beulahs night
And twofold Always. May God us keep
From Single vision & Newtons sleep"
In the Preface of The Book of Milton:
Bring me my Bow of burning gold;
Bring me my Arrows of desire:
Bring me my Spear: O clouds unfold!
Bring me my Chariot of fire
From Jerusalem, Plate 98, (E 257)
"A Sun of blood red wrath surrounding heaven on all sides around
Glorious incompreh[en]sible by Mortal Man & each Chariot was Sexual Threefold
And every Man stood Fourfold, each Four Faces had. One to the West
One toward the East One to the South One to the North. the Horses Fourfold
And the dim Chaos brightend beneath, above, around! Eyed as the PeacockAccording to the Human Nerves of Sensation, the Four Rivers of the Water of Life"